Alistair Evans

Global Survey of Outcomes of Neurocritical Care Patients: Analysis of the PRINCE Study Part 2

Publisher: Springer Science and Business Media LLC

Date: 04-09-2019

DOI: 10.1007/S12028-019-00835-Z

Abstract: Neurocritical care is devoted to the care of critically ill patients with acute neurological or neurosurgical emergencies. There is limited information regarding epidemiological data, disease characteristics, variability of clinical care, and in-hospital mortality of neurocritically ill patients worldwide. We addressed these issues in the Point PRevalence In Neurocritical CarE (PRINCE) study, a prospective, cross-sectional, observational study. We recruited patients from various intensive care units (ICUs) admitted on a pre-specified date, and the investigators recorded specific clinical care activities they performed on the subjects during their first 7 days of admission or discharge (whichever came first) from their ICUs and at hospital discharge. In this manuscript, we analyzed the final data set of the study that included patient admission characteristics, disease type and severity, ICU resources, ICU and hospital length of stay, and in-hospital mortality. We present descriptive statistics to summarize data from the case report form. We tested differences between geographically grouped data using parametric and nonparametric testing as appropriate. We used a multivariable logistic regression model to evaluate factors associated with in-hospital mortality. We analyzed data from 1545 patients admitted to 147 participating sites from 31 countries of which most were from North America (69%, N = 1063). Globally, there was variability in patient characteristics, admission diagnosis, ICU treatment team and resource allocation, and in-hospital mortality. Seventy-three percent of the participating centers were academic, and the most common admitting diagnosis was subarachnoid hemorrhage (13%). The majority of patients were male (59%), a half of whom had at least two comorbidities, and median Glasgow Coma Scale (GCS) of 13. Factors associated with in-hospital mortality included age (OR 1.03 95% CI, 1.02 to 1.04) lower GCS (OR 1.20 95% CI, 1.14 to 1.16 for every point reduction in GCS) pupillary reactivity (OR 1.8 95% CI, 1.09 to 3.23 for bilateral unreactive pupils) admission source (emergency room versus direct admission [OR 2.2 95% CI, 1.3 to 3.75] admission from a general ward versus direct admission [OR 5.85 95% CI, 2.75 to 12.45 and admission from another ICU versus direct admission [OR 3.34 95% CI, 1.27 to 8.8]) and the absence of a dedicated neurocritical care unit (NCCU) (OR 1.7 95% CI, 1.04 to 2.47). PRINCE is the first study to evaluate care patterns of neurocritical patients worldwide. The data suggest that there is a wide variability in clinical care resources and patient characteristics. Neurological severity of illness and the absence of a dedicated NCCU are independent predictors of in-patient mortality.

Fang evolution in venomous snakes: Adaptation of 3D tooth shape to the biomechanical properties of their prey

Publisher: Wiley

Date: 11-05-2021

DOI: 10.1111/EVO.14239

A third, remarkably small, tribosphenic mammal from the Mesozoic of Australia

Publisher: Springer International Publishing

Date: 2020

DOI: 10.1007/978-3-030-49753-8_3

A behavioural framework for the evolution of feeding in predatory aquatic mammals

Publisher: The Royal Society

Date: 03-2017

DOI: 10.1098/RSPB.2016.2750

Abstract: Extant aquatic mammals are a key component of aquatic ecosystems. Their morphology, ecological role and behaviour are, to a large extent, shaped by their feeding ecology. Nevertheless, the nature of this crucial aspect of their biology is often oversimplified and, consequently, misinterpreted. Here, we introduce a new framework that categorizes the feeding cycle of predatory aquatic mammals into four distinct functional stages (prey capture, manipulation and processing, water removal and swallowing), and details the feeding behaviours that can be employed at each stage. Based on this comprehensive scheme, we propose that the feeding strategies of living aquatic mammals form an evolutionary sequence that recalls the land-to-water transition of their ancestors. Our new conception helps to explain and predict the origin of particular feeding styles, such as baleen-assisted filter feeding in whales and raptorial ‘pierce’ feeding in pinnipeds, and informs the structure of present and past ecosystems.

Percussive underwater signaling in wild gray seals

Publisher: Wiley

Date: 31-01-2020

DOI: 10.1111/MMS.12666

Effects of allometry, productivity and lifestyle on rates and limits of body size evolution

Publisher: The Royal Society

Date: 07-08-2013

DOI: 10.1098/RSPB.2013.1007

Abstract: Body size affects nearly all aspects of organismal biology, so it is important to understand the constraints and dynamics of body size evolution. Despite empirical work on the macroevolution and macroecology of minimum and maximum size, there is little general quantitative theory on rates and limits of body size evolution. We present a general theory that integrates in idual productivity, the lifestyle component of the slow–fast life-history continuum, and the allometric scaling of generation time to predict a clade's evolutionary rate and asymptotic maximum body size, and the shape of macroevolutionary trajectories during ersifying phases of size evolution. We evaluate this theory using data on the evolution of clade maximum body sizes in mammals during the Cenozoic. As predicted, clade evolutionary rates and asymptotic maximum sizes are larger in more productive clades (e.g. baleen whales), which represent the fast end of the slow–fast lifestyle continuum, and smaller in less productive clades (e.g. primates). The allometric scaling exponent for generation time fundamentally alters the shape of evolutionary trajectories, so allometric effects should be accounted for in models of phenotypic evolution and interpretations of macroevolutionary body size patterns. This work highlights the intimate interplay between the macroecological and macroevolutionary dynamics underlying the generation and maintenance of morphological ersity.

Getting out of a mammalian egg: The egg tooth and caruncle of the echidna

Publisher: Cold Spring Harbor Laboratory

Date: 13-10-2021

DOI: 10.1101/2021.10.12.464116

Abstract: In the short-beaked echidna, Tachyglossus aculeatus , after an initial period of in utero development, the egg is laid in the pouch and incubated for 10 days. During this time, the fetuses develop an egg tooth and caruncle to help them hatch. However, there are only a few historical references that describe the development of the monotreme egg tooth. Using unprecedented access to echidna pre- and post-hatching tissues, the egg tooth and caruncle were assessed by micro-CT, histology and immunofluorescence, to map the changes at the morphological and molecular level. Unlike mammalian tooth germs that develop by invagination of a placode, the echidna egg tooth developed by evagination, similar to that of the first teeth in some reptiles. The egg tooth ankylosed to the premaxilla, rather than forming a mammalian thecodont attachment, with loss of the egg tooth post-hatching associated with high levels of odontoclasts, and apoptosis. The caruncle formed as a separate mineralisation from the adjacent nasal capsule, and as observed in birds and turtles, the nasal region epithelium expressed markers of cornification. Together, this highlights that the monotreme egg tooth shares many similarities with reptilian teeth, suggesting that this tooth is conserved from a common ancestor of mammals and reptiles.

Rhinocerotidae

Publisher: Springer Netherlands

Date: 2011

DOI: 10.1007/978-90-481-9962-4

Reply to comment by Kienle et al . 2017

Publisher: The Royal Society

Date: 27-09-2017

DOI: 10.1098/RSPB.2017.1836

Fang shape varies with ontogeny and sex in the venomous elapid snake Pseudonaja affinis

Publisher: Wiley

Date: 10-01-2022

DOI: 10.1002/JMOR.21442

Abstract: A predator's preferred prey often changes over the course of its life as it grows from an inexperienced juvenile through to a sexually mature adult. For species with highly specialised feeding strategies, this may require its anatomy to change over the course of its life. The dugite ( Pseudonaja affinis, Günther 1872) is a venomous snake from Australia that displays such a diet shift, with juveniles feeding on small reptiles, while adults mainly target mammals. We examined the morphology of fangs across both sexes and throughout ontogeny using geometric morphometrics and cross‐sectional sharpness measurements of key functional regions on these teeth. This highlighted key differences in shape that likely relate to the varied properties of their adult and juvenile diet. We found that juveniles display a more robust and blunter fang, which likely relates to feeding on scaly lizard prey, whereas adults have slender fangs with sharper tips, which reflects their diet of softer mammalian prey. There were also differences between males and females, with male snakes having significantly more slender fangs than females, which might be an indication of niche partitioning between the sexes. Using snout‐vent length as a proxy for age, we found that the ontogenetic shift in fang shape occurs when P. affinis is around 60 cm long, corresponding with previous studies that found this size to be the moment where these snakes switch from their juvenile to adult diet.

THE IMPACT OF REGIONAL CLIMATE ON THE EVOLUTION OF MAMMALS: A CASE STUDY USING FOSSIL HORSES

Publisher: Wiley

Date: 02-2010

DOI: 10.1111/J.1558-5646.2009.00830.X

Abstract: One of the classic ex les of faunal turnover in the fossil record is the Miocene transition from faunas dominated by anchitheriine horses with low-crowned molar teeth to faunas with hipparionine horses characterized by high-crowned teeth. The spread of hipparionine horses is associated with increased seasonality and the expansion of open habitats. It is generally accepted that anchitheriine horses did not display an evolutionary increase in tooth crown height prior to their extinction. Nevertheless, to test whether anchitheriines showed any changes interpretable as adaptation to local conditions, we analyzed molar teeth from multiple populations of Anchitherium in three dimensions. Our results show differences in tooth morphology that suggest incipient hypsodonty in Spain, the first region experiencing increasingly arid conditions in the early Miocene of Europe. Furthermore, analyses of tooth wear show that Spanish specimens cluster with present ungulates that eat foliage together with grasses and shrubs, whereas German specimens cluster with present-day ungulates that eat mostly foliage. Taken together, even a taxon such as Anchitherium, with a long and successful history of forest adaptation, did respond to regional environmental changes in an adaptive manner.

True seals achieved global distribution by breaking Bergmann's rule.

Publisher: Wiley

Date: 26-04-2022

DOI: 10.1111/EVO.14488

Abstract: True seals (phocids) have achieved a global distribution by crossing the equator multiple times in their evolutionary history. This is remarkable, as warm tropical waters are regarded as a barrier to marine mammal dispersal and-following Bergmann's rule-may have limited crossings to small-bodied species only. Here, we show that ancestral phocids were medium sized and did not obviously follow Bergmann's rule. Instead, they ranged across a broad spectrum of environmental temperatures, without undergoing shifts in temperature- or size-related evolutionary rates following dispersals across the equator. We conclude that the tropics have not constrained phocid biogeography.

The remarkable convergence of skull shape in crocodilians and toothed whales

Publisher: The Royal Society

Date: 08-03-2017

DOI: 10.1098/RSPB.2016.2348

Abstract: The striking resemblance of long-snouted aquatic mammals and reptiles has long been considered an ex le of morphological convergence, yet the true cause of this similarity remains untested. We addressed this deficit through three-dimensional morphometric analysis of the full ersity of crocodilian and toothed whale (Odontoceti) skull shapes. Our focus on biomechanically important aspects of shape allowed us to overcome difficulties involved in comparing mammals and reptiles, which have fundamental differences in the number and position of skull bones. We examined whether diet, habitat and prey size correlated with skull shape using phylogenetically informed statistical procedures. Crocodilians and toothed whales have a similar range of skull shapes, varying from extremely short and broad to extremely elongate. This spectrum of shapes represented more of the total variation in our dataset than between phylogenetic groups. The most elongate species (river dolphins and gharials) are extremely convergent in skull shape, clustering outside of the range of the other taxa. Our results suggest the remarkable convergence between long-snouted river dolphins and gharials is driven by diet rather than physical factors intrinsic to riverine environments. Despite erging approximately 288 million years ago, crocodilians and odontocetes have evolved a remarkably similar morphological solution to feeding on similar prey.

Macroecological and biogeographical patterns of limb reduction in the world's skinks

Publisher: Wiley

Date: 08-12-2022

DOI: 10.1111/JBI.14547

Abstract: Limb reduction is a dramatic evolutionary transition, yet whether it is achieved in similar trajectories across clades, and its environmental drivers, remain unclear. We investigate the macroevolutionary and biogeographical patterns of limb reduction in skinks, where limb reduction occurred more often than in any other tetrapod clade, and test their associations with substrate categories using a global database. We test for habitat associations of body shapes in a group of Australian skinks using quantitative habitat data. Global (Scincidae), Australia (Sphenomorphinae). Skinks, Australian Sphenomorphinae. We use morphological data to explore the patterns of limb reduction in the world's skinks, investigating how body proportions differ across skink clades and subfamilies. We examine the relationships between body shape and substrate (coarsely classified). Further, we investigate the relationships between body shape and high‐resolution soil and climate properties extracted from each species' distribution for Australian sphenomorphines. Relationships between limb lengths and trunk elongation show idiosyncratic patterns across skink clades. Presacral vertebrae numbers positively correlate with trunk elongation in all taxa, except Glaphyromorphus . Skinks from sandy habitats show greater disparity between forelimb and hindlimb lengths than all other substrate categories. In sphenomorphines, shorter limbs and elongated trunks correlate with colder, more humid microhabitats and richer soils high limb disparity correlates with hot, arid microhabitats and sandy, poor substrates. The evolutionary trajectories of limb reduction in skinks are clade‐specific and sometimes unique. Selection for specific limb proportions and body sizes in limb‐reduced forms changes across substrates. On poor, sandy substrates of arid environments, body shapes with longer hindlimbs may be more efficient for locomotion in a granular fluid (i.e. sand) and exploit the air–substrate interface than complete limblessness. On richer, more humid substrates, such morphology is rare, indicating that navigating cluttered substrates selects for more equal and shorter limb lengths.

The role of inhibitory dynamics in the loss and reemergence of macropodoid tooth traits

Publisher: Wiley

Date: 18-02-2016

DOI: 10.1111/EVO.12866

Abstract: The reversibility of phenotypic evolution is likely to be strongly influenced by the ability of underlying developmental systems to generate ancestral traits. However, few studies have quantitatively linked these developmental dynamics to traits that reevolve. In this study, we assess how changes in the inhibitory cascade, a developmental system that regulates relative tooth size in mammals, influenced the loss and reversals of the posthypocristid, a molar tooth crest, in the kangaroo superfamily Macropodoidea. We find that posthypocristid loss is linked with reduced levels of posterior molar inhibition, potentially driven by selection for lophodont, higher-crowned molar teeth. There is strong support for two posthypocristid reversals, each occurring after more than 15 million years of absence, in large-bodied species of Macropus, and two giant extinct species of short-faced sthenurine kangaroo (Procoptodon). We find that whereas primitive posthypocristid expression is linked to higher levels of posterior molar inhibition, reemergence is tied to a relative increase in third molar size associated with increasing body mass, producing molar phenotypes similar to those in mouse where the ectodysplasin pathway is upregulated. We argue that although shifts in the inhibitory cascade may enable reemergence, dietary ecology may limit the frequency of phylogenetic reversal.

First non-destructive internal imaging of Rangea, an icon of complex Ediacaran life

Publisher: Elsevier BV

Date: 09-2017

DOI: 10.1016/J.PRECAMRES.2017.07.023

Tooth wear development in the Australian Aboriginal dentition from Yuendumu: A longitudinal study

Publisher: Public Library of Science (PLoS)

Date: 09-07-2021

DOI: 10.1371/JOURNAL.PONE.0254151

Abstract: The analysis of dental wear, at both the microscopic and macroscopic scale, is one of the most widely used tools in archeology and anthropology to reconstruct the diet and lifestyle of past human populations. Biomechanical studies have indicated that tooth wear helps to dissipate the mechanical load over the crown surface, thus reducing the risk of tooth fracture. To date, there are only a few studies that have examined functional tooth wear variation in modern humans. Here we propose to study masticatory efficiency through the use of the Occlusal Fingerprint Analysis method, a well-developed digital approach that allows the reconstruction of the occlusal dynamics occurring during mastication. The aim of this study is to provide the first longitudinal quantitative data of molar and premolar macrowear patterns within a functional context. We examined the mixed and permanent dentition of one Australian Aboriginal child (from ages 8 to 17) from Yuendumu, using high-resolution surface scans of dental casts including both upper and lower arches. Our results suggest that the occlusal macrowear patterns of this in idual did not significantly change through time. Occlusal contact parameters such as functional area, inclination and direction remain relatively unaltered throughout childhood and adolescence, indicating little change in the masticatory function of this in idual. The functional tooth wear pattern in this in idual did not change longitudinally indicating the degree of masticatory efficiency has most probably remained unaltered.

Dental morphology ofAdalatherium hui(Mammalia, Gondwanatheria) from the LATE Cretaceous of Madagascar

Publisher: Informa UK Limited

Date: 14-12-2020

DOI: 10.1080/02724634.2020.1811292

Three‐dimensional (3D) geometric morphometric analysis of human premolars to assess sexual dimorphism and biological ancestry in Australian populations

Publisher: Wiley

Date: 15-02-2018

DOI: 10.1002/AJPA.23438

Abstract: This study aimed to investigate size and shape variation of human premolars between Indigenous Australians and Australians of European ancestry, and to assess whether sex and ancestry could be differentiated between these groups using 3D geometric morphometrics. Seventy dental casts from each group, equally sub ided by sex, were scanned using a structured-light scanner. The 3D meshes of upper and lower premolars were processed using geometric morphometric methods. Seventy-two landmarks were recorded for upper premolars and 50 landmarks for lower premolars. For each tooth type, two-way ANOVA was used to assess group differences in centroid size. Shape variations were explored using principal component analysis and visualized using 3D morphing. Two-way Procrustes ANOVA was applied to test group differences for ancestry and sex, and a "leave-one-out" discriminant function was applied to assess group assignment. Centroid size and shape did not display significant difference between the sexes. Centroid size was larger in Indigenous Australians for upper premolars and lower second premolars compared to the Australians of European ancestry. Significant shape variation was noted between the two ancestral groups for upper premolars and the lower first premolar. Correct group assignment of in idual teeth to their ancestral groups ranged between 80.0 and 92.8% for upper premolars and 60.0 and 75.7% for lower premolars. Our findings provide evidence of significant size and shape variation in human premolars between the two ancestral groups. High classification rates based on shape analysis of upper premolars highlight potential application of geometric morphometrics in anthropological, bioarcheological and forensic contexts.

A molecular and morphometric assessment of the systematics of the Macropus complex clarifies the tempo and mode of kangaroo evolution

Publisher: Oxford University Press (OUP)

Date: 28-03-2019

DOI: 10.1093/ZOOLINNEAN/ZLZ005

A panda-like diprotodontid? Assessing the diet of Hulitherium tomasettii using dental complexity (Orientation Patch Count Rotated) and dental microwear texture analysis

Publisher: Elsevier BV

Date: 12-2021

DOI: 10.1016/J.PALAEO.2021.110675

Acetaminophen for Fever in Critically Ill Patients with Suspected Infection

Publisher: Massachusetts Medical Society

Date: 03-12-2015

DOI: 10.1056/NEJMOA1508375

Confocal imaging, visualization and 3‐D surface measurement of small mammalian teeth

Publisher: Wiley

Date: 11-2001

DOI: 10.1046/J.1365-2818.2001.00939.X

Abstract: The difficulties traditionally faced by functional morphologists in representing and interpreting three-dimensional objects can now be mostly overcome using available laser and computer imaging technologies. A practical method for three-dimensional imaging of small mammalian teeth using confocal microscopy is reported. Moulding and casting of the teeth were first performed, followed by confocal fluorescence imaging. Accuracy and precision of the scanned structures were tested in morphometric studies by using a new technique to measure the noise in the scan of a three-dimensional surface, and linear and angular dimensions of the scans were compared with measurements made using traditional morphological tools. It is shown that measurements can be taken with less than 4% difference from the original object. Teeth of the microchiropteran bat Chalinolobus gouldii were scanned and measured to show the potential of the techniques. Methods for visualizing the small teeth in three-dimensional space, and animating the teeth in occlusion, show the power of this approach in aiding a three-dimensional understanding of the structure and function of teeth and other three-dimensional structures.

Elemental signatures of Australopithecus africanus teeth reveal seasonal dietary stress

Publisher: Springer Science and Business Media LLC

Date: 15-07-2019

DOI: 10.1038/S41586-019-1370-5

A Miocene pygmy right whale fossil from Australia

Publisher: PeerJ

Date: 22-06-2018

DOI: 10.7717/PEERJ.5025

Abstract: Neobalaenines are an enigmatic group of baleen whales represented today by a single living species: the pygmy right whale, Caperea marginata , found only in the Southern Hemisphere. Molecular ergence estimates date the origin of pygmy right whales to 22–26 Ma, yet so far there are only three confirmed fossil occurrences. Here, we describe an isolated periotic from the latest Miocene of Victoria (Australia). The new fossil shows all the hallmarks of Caperea , making it the second-oldest described neobalaenine, and the oldest record of the genus. Overall, the new specimen resembles C. marginata in its external morphology and details of the cochlea, but is more archaic in it having a hypertrophied suprameatal area and a greater number of cochlear turns. The presence of Caperea in Australian waters during the Late Miocene matches the distribution of the living species, and supports a southern origin for pygmy right whales.

The repeated evolution of dental apicobasal ridges in aquatic-feeding mammals and reptiles

Publisher: Oxford University Press (OUP)

Date: 15-04-2019

DOI: 10.1093/BIOLINNEAN/BLZ025

Functional ecological convergence between the thylacine and small prey-focused canids

Publisher: Springer Science and Business Media LLC

Date: 21-04-2021

DOI: 10.1186/S12862-021-01788-8

Abstract: Morphological convergence is a fundamental aspect of evolution, allowing for inference of the biology and ecology of extinct species by comparison with the form and function of living species as analogues. The thylacine ( Thylacinus cynocephalus ), the iconic recently extinct marsupial, is considered a classic ex le of convergent evolution with the distantly related placental wolf or dog, though almost nothing is actually known regarding its ecology. This lack of data leads to questions regarding the degree of convergence with, and the similarity of, the functional ecology of the thylacine and the wolf/dog. Here, we examined the cranium of the thylacine using 3D geometric morphometrics and two quantitative tests of convergence to more precisely determine convergent analogues, within a phylogenetically informed dataset of 56 comparative species across 12 families of marsupial and placental faunivorous mammals. Using this dataset, we investigated patterns of correlation between cranial shape and diet, phylogeny, and relative prey size across these terrestrial faunivores. We find a correlation between cranial, facial, and neurocranial shape and the ratio of prey-to-predator body mass, though neurocranial shape may not correlate with prey size within marsupials. The thylacine was found to group with predators that routinely take prey smaller than 45% of their own body mass, not with predators that take subequal-sized or larger prey. Both convergence tests find significant levels of convergence between the thylacine and the African jackals and South American ‘foxes’, with lesser support for the coyote and red fox. We find little support for convergence between the thylacine and the wolf or dog. Our study finds little support for a wolf/dog-like functional ecology in the thylacine, with it instead being most similar to mid-sized canids such as African jackals and South American ‘foxes’ that mainly take prey less than half their size. This work suggests that concepts of convergence should extend beyond superficial similarity, and broader comparisons can lead to false interpretations of functional ecology. The thylacine was a predator of small to mid-sized prey, not a big-game specialist like the placental wolf.

Shared patterns of segment size development in trilobites and vertebrates

Publisher: Oxford University Press (OUP)

Date: 19-04-2023

DOI: 10.1093/EVOLUT/QPAD057

Abstract: The relative sizes of body segments are a major determinant of the shape and functionality of an animal. Developmental biases affecting this trait can therefore have major evolutionary implications. In vertebrates, a molecular activator/inhibitor mechanism, known as the inhibitory cascade (IC), produces a simple and predictable pattern of linear relative size along successive segments. The IC model is considered the default mode of vertebrate segment development and has produced long-term biases in the evolution of serially homologous structures such as teeth, vertebrae, limbs, and digits. Here we investigate whether the IC model or an IC-like model also has controls on segment size development in an ancient and hyper erse group of extinct arthropods, the trilobites. We examined segment size patterning in 128 trilobite species, and during ontogenetic growth in three trilobite species. Linear relative segment size patterning is prominent throughout the trunk of trilobites in the adult form, and there is strict regulation of this patterning in newly developing segments in the pygidium. Extending the analysis to select stem and modern arthropods suggests that the IC is a common default mode of segment development capable of producing long-term biases in morphological evolution across arthropods as it does in vertebrates.

From Embryo to Adult: The Complete Development and Unusual Replacement of the Dentition of the Tammar Wallaby (Macropus eugenii)

Publisher: Springer Science and Business Media LLC

Date: 28-02-2022

DOI: 10.1007/S10914-021-09597-Y

Brief communication: Contributions of enamel-dentine junction shape and enamel deposition to primate molar crown complexity

Publisher: Wiley

Date: 2010

DOI: 10.1002/AJPA.21248

Abstract: Molar crown morphology varies among primates from relatively simple in some taxa to more complex in others, with such variability having both functional and taxonomic significance. In addition to the primary cusps, crown surface complexity derives from the presence of crests, cuspules, and crenulations. Developmentally, this complexity results from the deposition of an enamel cap over a basement membrane (the morphology of which is preserved as the enamel-dentine junction, or EDJ, in fully formed teeth). However, the relative contribution of the enamel cap and the EDJ to molar crown complexity is poorly characterized. In this study we examine the complexity of the EDJ and enamel surface of a broad s le of primate (including fossil hominin) lower molars through the application of micro-computed tomography and dental topographic analysis. Surface complexity of the EDJ and outer enamel surface (OES) is quantified by first mapping, and then summing, the total number of discrete surface orientation patches. We investigate the relative contribution of the EDJ and enamel cap to crown complexity by assessing the correlation in patch counts between the EDJ and OES within taxa and within in idual teeth. We identify three patterns of EDJ/OES complexity which demonstrate that both crown patterning early in development and the subsequent deposition of the enamel cap contribute to overall crown complexity in primates.

EVOLUTION OF MAMMAL TOOTH PATTERNS: NEW INSIGHTS FROM A DEVELOPMENTAL PREDICTION MODEL

Publisher: Wiley

Date: 05-2009

DOI: 10.1111/J.1558-5646.2009.00639.X

Abstract: The study of mammalian evolution is often based on insights into the evolution of teeth. Developmental studies may attempt to address the mechanisms that guide evolutionary changes. One ex le is the new developmental model proposed by Kavanagh et al. (2007), which provides a high-level testable model to predict mammalian tooth evolution. It is constructed on an inhibitory cascade model based on a dynamic balance of activators and inhibitors, regulating differences in molar size along the lower dental row. Nevertheless, molar sizes in some mammals differ from this inhibitory cascade model, in particular in voles. The aim of this study is to point out arvicoline and murine differences within this model and to suggest an alternative model. Here we demonstrate that the inhibitory cascade is not followed, due to the arvicoline's greatly elongated first lower molar. We broaden the scope of the macroevolutionary model by projecting a time scale onto the developmental model. We demonstrate that arvicoline evolution is rather characterized by a large gap from the oldest vole to more recent genera, with the rapid acquisition of a large first lower molar contemporaneous to their radiation. Our study provides alternative evolutionary hypotheses for mammals with different trajectories of development.

Inferring diet from dental morphology in terrestrial mammals

Publisher: Wiley

Date: 21-11-2016

DOI: 10.1111/2041-210X.12691

A universal power law for modelling the growth and form of teeth, claws, horns, thorns, beaks, and shells

Publisher: Springer Science and Business Media LLC

Date: 30-03-2021

DOI: 10.1186/S12915-021-00990-W

Abstract: A major goal of evolutionary developmental biology is to discover general models and mechanisms that create the phenotypes of organisms. However, universal models of such fundamental growth and form are rare, presumably due to the limited number of physical laws and biological processes that influence growth. One such model is the logarithmic spiral, which has been purported to explain the growth of biological structures such as teeth, claws, horns, and beaks. However, the logarithmic spiral only describes the path of the structure through space, and cannot generate these shapes. Here we show a new universal model based on a power law between the radius of the structure and its length, which generates a shape called a ‘power cone’. We describe the underlying ‘power cascade’ model that explains the extreme ersity of tooth shapes in vertebrates, including humans, mammoths, sabre-toothed cats, tyrannosaurs and giant megalodon sharks. This model can be used to predict the age of mammals with ever-growing teeth, including elephants and rodents. We view this as the third general model of tooth development, along with the patterning cascade model for cusp number and spacing, and the inhibitory cascade model that predicts relative tooth size. Beyond the dentition, this new model also describes the growth of claws, horns, antlers and beaks of vertebrates, as well as the fangs and shells of invertebrates, and thorns and prickles of plants. The power cone is generated when the radial power growth rate is unequal to the length power growth rate. The power cascade model operates independently of the logarithmic spiral and is present throughout erse biological systems. The power cascade provides a mechanistic basis for the generation of these pointed structures across the tree of life.

Ultrasonic hearing and echolocation in the earliest toothed whales

Publisher: The Royal Society

Date: 04-2016

DOI: 10.1098/RSBL.2016.0060

Abstract: The evolution of biosonar (production of high-frequency sound and reception of its echo) was a key innovation of toothed whales and dolphins (Odontoceti) that facilitated phylogenetic ersification and rise to ecological predominance. Yet exactly when high-frequency hearing first evolved in odontocete history remains a fundamental question in cetacean biology. Here, we show that archaic odontocetes had a cochlea specialized for sensing high-frequency sound, as exemplified by an Oligocene xenorophid, one of the earliest erging stem groups. This specialization is not as extreme as that seen in the crown clade. Paired with anatomical correlates for high-frequency signal production in Xenorophidae, this is strong evidence that the most archaic toothed whales possessed a functional biosonar system, and that this signature adaptation of odontocetes was acquired at or soon after their origin.

Dental phenomics: advancing genotype to phenotype correlations in craniofacial research

Publisher: Wiley

Date: 24-02-2014

DOI: 10.1111/ADJ.12156

Abstract: The field of dental phenomics provides many opportunities to elucidate the roles of genetic, epigenetic and environmental factors in craniofacial development. To date, research findings have helped to clarify the pathogenesis of many conditions, aiding diagnosis and clinical management. This paper provides an overview of dental phenomics research in some commonly encountered oral diseases in everyday clinical practice, as well as research relating to craniofacial growth and development. Clinically, advances in cariology and periodontology have led to better diagnostic capabilities and treatment provision. In the study of growth and development, important information regarding the varying clinical presentation and pathogenesis of many disorders is now apparent through the accurate quantification of phenotypes. Improvements in two-dimensional (2D) and three-dimensional (3D) imaging and analytical techniques have allowed for accurate dental phenotyping, and efforts are ongoing to apply these in vitro techniques to the in vivo setting. The field of dental phenomics represents an exciting avenue that links research findings to practical application, and collaboration between researcher and clinicians will help advance the field further.

A new large-bodied Pliocene seal with unusual cutting teeth

Publisher: The Royal Society

Date: 11-2020

DOI: 10.1098/RSOS.201591

Abstract: Today, monachine seals display the largest body sizes in pinnipeds. However, the evolution of larger body sizes has been difficult to assess due to the murky taxonomic status of fossil seals, including fossils referred to Callophoca obscura , a species thought to be present on both sides of the North Atlantic during the Neogene. Several studies have recently called into question the taxonomic validity of these fossils, especially those from the USA, as the fragmentary lectotype specimen from Belgium is of dubious diagnostic value. We find that the lectotype isolated humerus of C. obscura is too uninformative thus, we designate C. obscura as a nomen dubium. More complete cranial and postcranial specimens from the Pliocene Yorktown Formation are described as a new taxon, Sarcodectes magnus . The cranial specimens display adaptations towards an enhanced ability to cut or chew prey that are unique within Phocidae, and estimates indicate S. magnus to be around 2.83 m in length. A parsimony phylogenetic analysis found S. magnus is a crown monachine. An ancestral state estimation of body length indicates that monachines did not have a remarkable size increase until the evolution of the lobodontins and miroungins.

Convergent evolution of an extreme dietary specialisation, the olfactory system of worm-eating rodents

Publisher: Springer Science and Business Media LLC

Date: 13-12-2018

DOI: 10.1038/S41598-018-35827-0

Abstract: Turbinal bones are key components of the mammalian rostrum that contribute to three critical functions: (1) homeothermy, (2) water conservation and (3) olfaction. With over 700 extant species, murine rodents (Murinae) are the most species-rich mammalian subfamily, with most of that ersity residing in the Indo-Australian Archipelago. Their evolutionary history includes several cases of putative, but untested ecomorphological convergence, especially with traits related to diet. Among the most spectacular rodent ecomorphs are the vermivores which independently evolved in several island systems. We used 3D CT-scans (N = 87) of murine turbinal bones to quantify olfactory capacities as well as heat or water conservation adaptations. We obtained similar results from an existing 2D complexity method and two new 3D methodologies that quantify bone complexity. Using comparative phylogenetic methods, we identified a significant convergent signal in the rostral morphology within the highly specialised vermivores. Vermivorous species have significantly larger and more complex olfactory turbinals than do carnivores and omnivores. Increased olfactory capacities may be a major adaptive feature facilitating rats’ capacity to prey on elusive earthworms. The narrow snout that characterises vermivores exhibits significantly reduced respiratory turbinals, which may reduce their heat and water conservation capacities.

The evolution of high dental complexity in the horse lineage

Publisher: Finnish Zoological and Botanical Publishing Board

Date: 04-2014

DOI: 10.5735/086.051.0209

Adaptive radiation of multituberculate mammals before the extinction of dinosaurs

Publisher: Springer Science and Business Media LLC

Date: 03-2012

DOI: 10.1038/NATURE10880

Abstract: The Cretaceous-Paleogene mass extinction approximately 66 million years ago is conventionally thought to have been a turning point in mammalian evolution. Prior to that event and for the first two-thirds of their evolutionary history, mammals were mostly confined to roles as generalized, small-bodied, nocturnal insectivores, presumably under selection pressures from dinosaurs. Release from these pressures, by extinction of non-avian dinosaurs at the Cretaceous-Paleogene boundary, triggered ecological ersification of mammals. Although recent in idual fossil discoveries have shown that some mammalian lineages ersified ecologically during the Mesozoic era, comprehensive ecological analyses of mammalian groups crossing the Cretaceous-Paleogene boundary are lacking. Such analyses are needed because ersification analyses of living taxa allow only indirect inferences of past ecosystems. Here we show that in arguably the most evolutionarily successful clade of Mesozoic mammals, the Multituberculata, an adaptive radiation began at least 20 million years before the extinction of non-avian dinosaurs and continued across the Cretaceous-Paleogene boundary. Disparity in dental complexity, which relates to the range of diets, rose sharply in step with generic richness and disparity in body size. Moreover, maximum dental complexity and body size demonstrate an adaptive shift towards increased herbivory. This dietary expansion tracked the ecological rise of angiosperms and suggests that the resources that were available to multituberculates were relatively unaffected by the Cretaceous-Paleogene mass extinction. Taken together, our results indicate that mammals were able to take advantage of new ecological opportunities in the Mesozoic and that at least some of these opportunities persisted through the Cretaceous-Paleogene mass extinction. Similar broad-scale ecomorphological inventories of other radiations may help to constrain the possible causes of mass extinctions.

Plicidentine and the repeated origins of snake venom fangs

Publisher: The Royal Society

Date: 11-08-2021

DOI: 10.1098/RSPB.2021.1391

Abstract: Snake fangs are an iconic exemplar of a complex adaptation, but despite striking developmental and morphological similarities, they probably evolved independently in several lineages of venomous snakes. How snakes could, uniquely among vertebrates, repeatedly evolve their complex venom delivery apparatus is an intriguing question. Here we shed light on the repeated evolution of snake venom fangs using histology, high-resolution computed tomography (microCT) and biomechanical modelling. Our examination of venomous and non-venomous species reveals that most snakes have dentine infoldings at the bases of their teeth, known as plicidentine, and that in venomous species, one of these infoldings was repurposed to form a longitudinal groove for venom delivery. Like plicidentine, venom grooves originate from infoldings of the developing dental epithelium prior to the formation of the tooth hard tissues. Derivation of the venom groove from a large plicidentine fold that develops early in tooth ontogeny reveals how snake venom fangs could originate repeatedly through the co-option of a pre-existing dental feature even without close association to a venom duct. We also show that, contrary to previous assumptions, dentine infoldings do not improve compression or bending resistance of snake teeth during biting plicidentine may instead have a role in tooth attachment.

Taking a stab at modelling canine tooth biomechanics in mammalian carnivores with beam theory and finite-element analysis

Publisher: The Royal Society

Date: 10-2022

DOI: 10.1098/RSOS.220701

Abstract: Canine teeth are vital to carnivore feeding ecology, facilitating behaviours related to prey capture and consumption. Forms vary with specific feeding ecologies however, the biomechanics that drive these relationships have not been comprehensively investigated. Using a combination of beam theory analysis (BTA) and finite-element analysis (FEA) we assessed how aspects of canine shape impact tooth stress, relating this to feeding ecology. The degree of tooth lateral compression influenced tolerance of multidirectional loads, whereby canines with more circular cross-sections experienced similar maximum stresses under pulling and shaking loads, while more ellipsoid canines experienced higher stresses under shaking loads. Robusticity impacted a tooth's ability to tolerate stress and appears to be related to prey materials. Robust canines experience lower stresses and are found in carnivores regularly encountering hard foods. Slender canines experience higher stresses and are associated with carnivores biting into muscle and flesh. Curvature did not correlate with tooth stress however, it did impact bending during biting. Our simulations help identify scenarios where canine forms are likely to break and pinpoint areas where this breakage may occur. These patterns demonstrate how canine shape relates to tolerating the stresses experienced when killing and feeding, revealing some of the form–function relationships that underpin mammalian carnivore ecologies.

A rare observation of group prey processing in wild leopard seals (Hydrurga leptonyx)

Publisher: Springer Science and Business Media LLC

Date: 08-2019

DOI: 10.1007/S00300-019-02542-Z

Spatial and functional modeling of carnivore and insectivore molariform teeth

Publisher: Wiley

Date: 06-2006

DOI: 10.1002/JMOR.10285

Abstract: The interaction between the two main competing geometric determinants of teeth (the geometry of function and the geometry of occlusion) were investigated through the construction of three-dimensional spatial models of several mammalian tooth forms (carnassial, insectivore premolar, zalambdodont, dilambdodont, and tribosphenic). These models aim to emulate the shape and function of mammalian teeth. The geometric principles of occlusion relating to single- and double-crested teeth are reviewed. Function was considered using engineering principles that relate tooth shape to function. Substantial similarity between the models and mammalian teeth were achieved. Differences between the two indicate the influence of tooth strength, geometric relations between upper and lower teeth (including the presence of the protocone), and wear on tooth morphology. The concept of "autocclusion" is expanded to include any morphological features that ensure proper alignment of cusps on the same tooth and other teeth in the tooth row. It is concluded that the tooth forms examined are auto-aligning, and do not require additional morphological guides for correct alignment. The model of therian molars constructed by Crompton and Sita-Lumsden ([1970] Nature 227:197-199) is reconstructed in 3D space to show that their hypothesis of crest geometry is erroneous, and that their model is a special case of a more general class of models.

Gigantic mysticete predators roamed the Eocene Southern Ocean

Publisher: Cambridge University Press (CUP)

Date: 04-2019

DOI: 10.1017/S095410201800055X

Abstract: Modern baleen whales (Mysticeti), the largest animals on Earth, arose from small ancestors around 36.4 million years ago (Ma). True gigantism is thought to have arisen late in mysticete history, with species exceeding 10 m unknown prior to 8 Ma. This view is challenged by new fossils from Seymour Island (Isla Marambio), Antarctica, which suggest that enormous whales once roamed the Southern Ocean during the Late Eocene ( c . 34 Ma). The new material hints at an unknown species of the archaic mysticete Llanocetus with a total body length of up to 12 m. The latter is comparable to that of extant Omura's whales ( Balaenoptera omurai Wada et al . 2003), and suggests that gigantism has been a re-occurring feature of mysticetes since their very origin. Functional analysis including sharpness and dental wear implies an at least partly raptorial feeding strategy, starkly contrasting with the filtering habit of living whales. The new material markedly expands the size range of archaic mysticetes, and demonstrates that whales achieved considerable disparity shortly after their origin.

Automated 3D Phenotype Analysis Using Data Mining

Publisher: Public Library of Science (PLoS)

Date: 05-03-2008

DOI: 10.1371/JOURNAL.PONE.0001742

Open data and digital morphology

Publisher: The Royal Society

Date: 12-04-2017

DOI: 10.1098/RSPB.2017.0194

Abstract: Over the past two decades, the development of methods for visualizing and analysing specimens digitally, in three and even four dimensions, has transformed the study of living and fossil organisms. However, the initial promise that the widespread application of such methods would facilitate access to the underlying digital data has not been fully achieved. The underlying datasets for many published studies are not readily or freely available, introducing a barrier to verification and reproducibility, and the reuse of data. There is no current agreement or policy on the amount and type of data that should be made available alongside studies that use, and in some cases are wholly reliant on, digital morphology. Here, we propose a set of recommendations for minimum standards and additional best practice for three-dimensional digital data publication, and review the issues around data storage, management and accessibility.

Brain size evolution in whales and dolphins: new data from fossil mysticetes

Publisher: Oxford University Press (OUP)

Date: 10-05-2021

DOI: 10.1093/BIOLINNEAN/BLAB054

Abstract: Cetaceans (whales and dolphins) have some of the largest and most complex brains in the animal kingdom. When and why this trait evolved remains controversial, with proposed drivers ranging from echolocation to foraging complexity and high-level sociality. This uncertainty partially reflects a lack of data on extinct baleen whales (mysticetes), which has obscured deep-time patterns of brain size evolution in non-echolocating cetaceans. Building on new measurements from mysticete fossils, we show that the evolution of large brains preceded that of echolocation, and subsequently followed a complex trajectory involving several independent increases (e.g. in rorquals and oceanic dolphins) and decreases (e.g. in right whales and ‘river dolphins’). Echolocating whales show a greater tendency towards large brain size, thus reaffirming cognitive demands associated with sound processing as a plausible driver of cetacean encephalization. Nevertheless, our results suggest that other factors such as sociality were also important.

Traditional and digital examination of the baculum of a leopard seal (Hydrurga leptonyx)

Publisher: Wiley

Date: 04-09-2023

DOI: 10.1111/MMS.13067

Torn limb from limb: the ethology of prey-processing in Tasmanian devils (

Publisher: CSIRO Publishing

Date: 09-08-2021

DOI: 10.1071/AM21006

Abstract: The success of carnivorous mammals is determined not only by their ability to locate and kill prey, but also their efficiency at consuming it. Breaking large prey into small pieces is challenging due to the strong and tough materials that make up a carcass (e.g. hide, muscle, and bone). Carnivores therefore require a erse suite of prey-processing behaviours to utilise their catch. Tasmanian devils are Australia’s only large marsupial scavengers and have the ability to consume almost all of a carcass. To determine how they do this we analysed 5.5 hours of footage from 21 captive and wild devils feeding at carcasses. We documented 6320 bouts of 12 distinct prey-processing behaviours, performed at frequencies that varied throughout feeds and between groups. The time point in the feed influenced the types of behaviours used. This is likely due to changing prey size, as different techniques appear better suited to handling whole carcasses or large pieces (pulling and pinning) or smaller pieces (holding and manipulating). Group size impacted the frequency of social pulling behaviours, which increased with the number of animals. Our findings highlight the range of prey-processing behaviours performed by scavenging devils when handling, breaking down, and consuming a carcass. The devils’ repertoire shares similarities with large carnivores that handle and consume whole carcasses as well as small carnivores that are adept in grasping and handling smaller prey.

Patterns of maximum body size evolution in Cenozoic land mammals: eco-evolutionary processes and abiotic forcing

Publisher: The Royal Society

Date: 07-06-2014

DOI: 10.1098/RSPB.2013.2049

Abstract: There is accumulating evidence that macroevolutionary patterns of mammal evolution during the Cenozoic follow similar trajectories on different continents. This would suggest that such patterns are strongly determined by global abiotic factors, such as climate, or by basic eco-evolutionary processes such as filling of niches by specialization. The similarity of pattern would be expected to extend to the history of in idual clades. Here, we investigate the temporal distribution of maximum size observed within in idual orders globally and on separate continents. While the maximum size of in idual orders of large land mammals show differences and comprise several families, the times at which orders reach their maximum size over time show strong congruence, peaking in the Middle Eocene, the Oligocene and the Plio-Pleistocene. The Eocene peak occurs when global temperature and land mammal ersity are high and is best explained as a result of niche expansion rather than abiotic forcing. Since the Eocene, there is a significant correlation between maximum size frequency and global temperature proxy. The Oligocene peak is not statistically significant and may in part be due to s ling issues. The peak in the Plio-Pleistocene occurs when global temperature and land mammal ersity are low, it is statistically the most robust one and it is best explained by global cooling. We conclude that the macroevolutionary patterns observed are a result of the interplay between eco-evolutionary processes and abiotic forcing.

Skeleton of a Cretaceous mammal from Madagascar reflects long-term insularity

Publisher: Springer Science and Business Media LLC

Date: 29-04-2020

DOI: 10.1038/S41586-020-2234-8

Predicting evolutionary patterns of mammalian teeth from development

Publisher: Springer Science and Business Media LLC

Date: 09-2007

DOI: 10.1038/NATURE06153

Abstract: One motivation in the study of development is the discovery of mechanisms that may guide evolutionary change. Here we report how development governs relative size and number of cheek teeth, or molars, in the mouse. We constructed an inhibitory cascade model by experimentally uncovering the activator-inhibitor logic of sequential tooth development. The inhibitory cascade acts as a ratchet that determines molar size differences along the jaw, one effect being that the second molar always makes up one-third of total molar area. By using a macroevolutionary test, we demonstrate the success of the model in predicting dentition patterns found among murine rodent species with various diets, thereby providing an ex le of ecologically driven evolution along a developmentally favoured trajectory. In general, our work demonstrates how to construct and test developmental rules with evolutionary predictability in natural systems.

What very big teeth you have Mammal Teeth: Origin, Evolution, and Diversity

Publisher: Oxford University Press (OUP)

Date: 2012

DOI: 10.1525/BIO.2012.62.1.16

Wearing the devil down: Rate of tooth wear varies between wild and captive Tasmanian devils

Publisher: Wiley

Date: 08-06-2021

DOI: 10.1002/ZOO.21632

Abstract: Mammalian carnivores rely on their sharp teeth to effectively kill and consume prey. However, over time this causes wear and breakage that alters tooth shape, reducing their effectiveness. Extreme tooth wear and damage is especially prevalent in species that scavenge carcasses, like the Tasmanian devil ( Sarcophilus harrisii ), which are well known for their voracious appetites and ability to consume almost all of a carcass, including bone. In this study, we comprehensively describe tooth wear in captive and wild devils to look for differences in the patterns and rate of wear between these environments. To do this we surveyed tooth condition in skulls from 182 wild and 114 captive devils for which age was estimated using canine over‐eruption. We found the types of tooth wear documented were the same in captive and wild devils, but captive animals have less severe wear than wild devils of the same estimated age. There was no difference in the proportion of captive or wild in iduals with broken canine or molar teeth however, breakage occurred at a younger age in wild devils. Although not considered anomalous or harmful, this indicates a difference in the way teeth are being used and/or the foods consumed between captive and wild devils. We hypothesize how these results relate to differences in diet or behavior that may stem from their various feeding environments, for ex le, higher quality food (fresh, whole, and yet to be scavenged carcasses) provided to captive devils likely causes less wear. Further, we support management options that closely replicate wild diet items and behaviors suitable for a long‐term insurance population.

Inferring diet, feeding behaviour and causes of mortality from prey-induced injuries in a New Zealand fur seal

Publisher: Inter-Research Science Center

Date: 30-04-2020

DOI: 10.3354/DAO03473

Abstract: New Zealand fur seals Arctocephalus forsteri are the most abundant of the 4 otariid (eared seal) species distributed across Australasia. Analyses of stomach contents, scats and regurgitates suggest a diet dominated by bony fish and squid, with cartilaginous species (e.g. sharks and rays) either absent or underrepresented because of a lack of preservable hard parts. Here we report on a subadult specimen from south-eastern Australia, which was found ashore emaciated and with numerous puncture wounds across its lips, cheeks, throat and the inside of its oral cavity. Fish spines embedded in the carcass revealed that these injuries were inflicted by chimaeras and myliobatiform rays (stingrays and relatives), which matches reports on the diet of A. forsteri from New Zealand, but not South Australia. Shaking and tearing of prey at the surface may help to avoid ingestion of the venomous spines, perhaps contributing to their absence from scats and regurgitates. Nevertheless, the number and severity of the facial stab wounds, some of which led to local necrosis, likely affected the animal’s ability to feed, and may account for its death. Despite their detrimental effects, fish spine-related injuries are difficult to spot, and may be a common, albeit cryptic, type of trauma. We therefore recommend that stranded seals be systematically examined for this potentially life-threatening pathology.

Connecting morphology, function and tooth wear in microchiropterans

Publisher: Oxford University Press (OUP)

Date: 25-04-2005

DOI: 10.1111/J.1095-8312.2005.00474.X

GENERA ARE OFTEN BETTER THAN SPECIES FOR DETECTING EVOLUTIONARY CHANGE IN THE FOSSIL RECORD: A REPLY TO SALESA ET AL.

Publisher: Wiley

Date: 27-01-2011

DOI: 10.1111/J.1558-5646.2011.01220.X

The Unique Penile Morphology of the Short-Beaked Echidna, Tachyglossus aculeatus

Publisher: S. Karger AG

Date: 2021

DOI: 10.1159/000515145

Abstract: Monotremes erged from therian mammal ancestors approximately 184 million years ago and have a number of novel reproductive characteristics. One in particular is their penile morphology. There are differences between echidna and platypus phalluses, but both are somewhat similar in structure to the reptilian phallus. The echidna penis consists of 4 rosette glans, each of which contains a termination of the quadrifurcate urethra, but it appears that only 2 of the 4 glans become erect at any one time. Despite this, only a few historical references describe the structure of the echidna penis and none provides an explanation for the mechanisms of unilateral ejaculation. This study confirmed that the echidna penis contains many of the same overall structures and morphology as other mammalian penises and a number of features homologous with reptiles. The corpus cavernosum is well supplied with blood, extends up to the base of the glans penis and is primarily responsible for erection. However, the echidna possesses 2 distinct corpora spongiosa separated by a septum, each of which surround the urethra only distal to the initial urethral bifurcation in the glans penis. Together with the bifurcation of the main penile artery, this provides a mechanism by which blood flow could be directed to only one corpus spongiosum at a time to maintain an open urethra that supplies 2 of the 4 glans to facilitate unilateral ejaculation.

Second specimen of Corriebaatar marywaltersae from the Lower Cretaceous of Australia confirms its multituberculate affinities

Publisher: Polska Akademia Nauk Instytut Paleobiologii (Institute of Paleobiology, Polish Academy of Sciences)

Date: 2022

DOI: 10.4202/APP.00924.2021

The tooth of perfection: functional and spatial constraints on mammalian tooth shape

Publisher: Oxford University Press (OUP)

Date: 31-01-2003

DOI: 10.1046/J.1095-8312.2003.00146.X

Getting out of a mammalian egg: the egg tooth and caruncle of the echidna

Publisher: Elsevier BV

Date: 03-2023

DOI: 10.1016/J.YDBIO.2022.12.005

The mandible and dentition of the Early Cretaceous monotreme Teinolophos trusleri

Publisher: Informa UK Limited

Date: 23-06-2016

DOI: 10.1080/03115518.2016.1180034

Multi-proxy dentition analyses reveal niche partitioning between sympatric herbivorous dinosaurs

Publisher: Springer Science and Business Media LLC

Date: 02-12-2022

DOI: 10.1038/S41598-022-24816-Z

Abstract: Dentitions of the sympatric herbivorous dinosaurs Hungarosaurus (Ankylosauria, Nodosauridae) and Mochlodon (Ornithopoda, Rhabdodontidae) (Santonian, Hungary) were analysed to investigate their dietary ecology, using several complementary methods—orientation patch count, tooth replacement rate, macrowear, tooth wear rate, traditional microwear, and dental microwear texture analysis (DMTA). Tooth formation time is similar in Hungarosaurus and Mochlodon , and traditional and DMTA microwear features suggest low-browsing habits for both taxa, consistent with their inferred stances and body sizes. However, Mochlodon possesses a novel adaptation for increasing dental durability: the dentine on the working side of the crown is double the thickness of that on the balancing side. Moreover, crown morphology, enamel thickness, macrowear orientation, and wear rate differ greatly between the two taxa. Consequently, these sympatric herbivores probably exploited plants of different toughness, implying dietary selectivity and niche partitioning. Hungarosaurus is inferred to have eaten softer vegetation, whereas Mochlodon likely fed on tougher material. Compared to the much heavier, quadrupedal Hungarosaurus , the bipedal Mochlodon wore down more than twice as much of its crown volume during the functional life of the tooth. This heavy tooth wear might correlate with more intensive food processing and, in turn, could reflect differences in the metabolic requirements of these animals.

Replaying evolutionary transitions from the dental fossil record

Publisher: Springer Science and Business Media LLC

Date: 30-07-2014

DOI: 10.1038/NATURE13613

High-level similarity of dentitions in carnivorans and rodents

Publisher: Springer Science and Business Media LLC

Date: 13-12-2006

DOI: 10.1038/NATURE05433

Abstract: The study of mammalian evolution depends greatly on understanding the evolution of teeth and the relationship of tooth shape to diet. Links between gross tooth shape, function and diet have been proposed since antiquity, stretching from Aristotle to Cuvier, Owen and Osborn. So far, however, the possibilities for exhaustive, quantitative comparisons between greatly different tooth shapes have been limited. Cat teeth and mouse teeth, for ex le, are fundamentally distinct in shape and structure as a result of independent evolutionary change over tens of millions of years. There is difficulty in establishing homology between their tooth components or in summarizing their tooth shapes, yet both carnivorans and rodents possess a comparable spectrum of dietary specializations from animals to plants. Here we introduce homology-free techniques to measure the phenotypic complexity of the three-dimensional shape of tooth crowns. In our geographic information systems (GIS) analysis of 441 teeth from 81 species of carnivorans and rodents, we show that the surface complexity of tooth crowns directly reflects the foods they consume. Moreover, the absolute values of dental complexity for in idual dietary classes correspond between carnivorans and rodents, illustrating a high-level similarity between overall tooth shapes despite a lack of low-level similarity of specific tooth components. These results suggest that scale-independent forces have determined the high-level dental shape in lineages that are widely ergent in size, ecology and life history. This link between diet and phenotype will be useful for inferring the ecology of extinct species and illustrates the potential of fast-throughput, high-level analysis of the phenotype.

Reduction of in‐hospital cardiac arrest rates in intensive care‐equipped New South Wales hospitals in association with implementation of Between the Flags rapid response system

Publisher: Wiley

Date: 03-2021

DOI: 10.1111/IMJ.14812

Dental macrowear reveals ecological diversity of Gorilla spp.

Publisher: Springer Science and Business Media LLC

Date: 02-06-2022

DOI: 10.1038/S41598-022-12488-8

Abstract: Size and shape variation of molar crowns in primates plays an important role in understanding how species adapted to their environment. Gorillas are commonly considered to be folivorous primates because they possess sharp cusped molars which are adapted to process fibrous leafy foods. However, the proportion of fruit in their diet can vary significantly depending on their habitats. While tooth morphology can tell us what a tooth is capable of processing, tooth wear can help us to understand how teeth have been used during mastication. The objective of this study is to explore if differences in diet at the subspecies level can be detected by the analysis of molar macrowear. We analysed a large s le of second lower molars of Grauer’s, mountain and western lowland gorilla by combining the Occlusal Fingerprint Analysis method with other dental measurements. We found that Grauer’s and western lowland gorillas are characterised by a macrowear pattern indicating a larger intake of fruit in their diet, while mountain gorilla’s macrowear is associated with the consumption of more folivorous foods. We also found that the consumption of herbaceous foods is generally associated with an increase in dentine and enamel wear, confirming the results of previous studies.

Findings of the first ANZICS conference on the role of intensive care in rapid response teams

Publisher: SAGE Publications

Date: 05-2015

DOI: 10.1177/0310057X1504300314

Abstract: Rapid Response Teams (RRTs) are specialised teams introduced into hospitals to improve the outcomes of deteriorating ward patients. Although Rapid Response Systems (RRSs) were developed by the intensive care unit (ICU) community, there is variability in their delivery, and consultant involvement, supervision and leadership appears to be relatively infrequent. In July 2014, the Australian and New Zealand Intensive Care Society (ANZICS) convened the first conference on the role of intensive care medicine in RRTs in Australia and New Zealand. The conference explored RRSs in the broader role of patient safety, resourcing and staffing of RRTs, effect on ICU workload, different RRT models, the outcomes of RRT patients and original research projects in the area of RRSs. Issues around education and training of both ICU registrars and nurses were examined, and the role of team training explored. Measures to assess the effectiveness of the RRS and RRT at the level of health system and hospital, team performance and team effectiveness were discussed, and the need to develop a bi-national ANZICS RRT patient database was presented. Strategies to prevent patient deterioration in the ‘pre-RRT’ period were discussed, including education of ward nurses and doctors, as well as an overarching governance structure. The role of the ICU in deteriorating ward patients was debated and an integrated model of acute care presented. This article summarises the findings of the conference and presents recommendations on the role of intensive care medicine in RRTs in Australia and New Zealand.

The relationship between diet and body mass in terrestrial mammals

Publisher: Cambridge University Press (CUP)

Date: 18-03-2016

DOI: 10.1017/PAB.2016.6

Abstract: Diet and body mass are highly important factors in mammalian ecology, and they have also proven to be powerful paleoecological indicators. Our previous research has proposed a new classification scheme for mammals with more dietary isions that emphasizes the primary resource in a given diet. We analyzed a database summarizing the dietary preferences of 139 species of marsupial and placental terrestrial mammals (including 14 orders) and their average body masses in order to explore whether this new classification better highlights ecomorphological differences between species. Additionally, the dietary ersity of every species in the data set was quantified by applying the inverse Simpson index to stomach content percentages. We observed a decrease in maximum dietary ersity with increasing body mass. Having lower requirements for energy and nutrients per unit of body weight or ecological advantages such as larger home ranges allows larger mammals to feed on less nutritive feeding resources (i.e., structural plant material). Our results also suggest that body-size ranges are different across dietary specializations. Smaller mammals ( kg) are mainly insectivores, granivores, or mixed feeders, while bigger animals ( kg) are usually either carnivores or herbivores that feed specifically on grasses and leaves. The medium-size range (1–30 kg) is mostly composed of frugivorous species that inhabit tropical and subtropical rain forests. Thus, the near absence of medium-sized mammals in open environments such as savannas can be linked to the decreasing density of fruit trees needed to support a pure frugivorous diet year-round. In other words, seasonality of precipitation prevents species from specializing on a totally frugivorous diet. Our results suggest that this new classification scheme correlates well with body mass, one of the most studied morphological variables in paleoecology and ecomorphology. Therefore, the classification should serve as a useful basis for future paleoclimatological studies.

Challenges and opportunities for innovation in bioinformed sustainable materials

Publisher: Springer Science and Business Media LLC

Date: 04-10-2023

DOI: 10.1038/S43246-023-00405-Z

Suction causes novel tooth wear in marine mammals, with implications for feeding evolution in baleen whales

Publisher: Springer Science and Business Media LLC

Date: 23-01-2023

DOI: 10.1007/S10914-022-09645-1

First monk seal from the Southern Hemisphere rewrites the evolutionary history of true seals

Publisher: The Royal Society

Date: 11-11-2020

DOI: 10.1098/RSPB.2020.2318

Abstract: Living true seals (phocids) are the most widely dispersed semi-aquatic marine mammals, and comprise geographically separate northern (phocine) and southern (monachine) groups. Both are thought to have evolved in the North Atlantic, with only two monachine lineages—elephant seals and lobodontins—subsequently crossing the equator. The third and most basal monachine tribe, the monk seals, have hitherto been interpreted as exclusively northern and (sub)tropical throughout their entire history. Here, we describe a new species of extinct monk seal from the Pliocene of New Zealand, the first of its kind from the Southern Hemisphere, based on one of the best-preserved and richest s les of seal fossils worldwide. This unanticipated discovery reveals that all three monachine tribes once coexisted south of the equator, and forces a profound revision of their evolutionary history: rather than primarily ersifying in the North Atlantic, monachines largely evolved in the Southern Hemisphere, and from this southern cradle later reinvaded the north. Our results suggest that true seals crossed the equator over eight times in their history. Overall, they more than double the age of the north–south dichotomy characterizing living true seals and confirms a surprisingly recent major change in southern phocid ersity.

Three-dimensional mammalian tooth development using diceCT

Publisher: Elsevier BV

Date: 2018

DOI: 10.1016/J.ARCHORALBIO.2017.10.018

Abstract: This study aims to develop the Diffusible Iodine-based Contrast-Enhanced CT (diceCT) method for non-destructive imaging of both soft and mineralised tissues. We sought to document the 3D spatio-temporal pattern of mammalian tooth development including multiple tooth classes and generations, using the tammar wallaby (Macropus eugenii) as a model species. We took microCT scans of developing fetuses and pouch young stained using Lugol's Iodine (I DiceCT dramatically enhanced visual contrast of soft tissues, allowing differentiation between epithelial and mesenchymal layers. Subvolume scans at higher magnification achieved single-cell layer resolution within relatively large intact heads. We observed in-situ initiating teeth, which progressed through major stages of tooth development including morphogenesis and mineralisation. In addition, we traced the development of other mineralized and unmineralised tissues, such as the cranial bones and the brain, eye and olfactory system. DiceCT was time- and cost-effective in producing complex 3D models of the entire dentition of the tammar wallaby at each developmental stage with tissue-level resolution. The 3D view of soft and mineralised tooth structures allowed us to define tooth class and generation from a developmental perspective. Additionally, the development of other organs can also be documented using the same scans, demonstrating the efficiency and versatility of this technique.

The cochlea of the enigmatic pygmy right whale Caperea marginata informs mysticete phylogeny

Publisher: Wiley

Date: 23-03-2017

DOI: 10.1002/JMOR.20674

Abstract: The pygmy right whale, Caperea marginata, is the least understood extant baleen whale (Cetacea, Mysticeti). Knowledge on its basic anatomy, ecology, and fossil record is limited, even though its singular position outside both balaenids (right whales) and balaenopteroids (rorquals + grey whales) gives Caperea a pivotal role in mysticete evolution. Recent investigations of the cetacean cochlea have provided new insights into sensory capabilities and phylogeny. Here, we extend this advance to Caperea by describing, for the first time, the inner ear of this enigmatic species. The cochlea is large and appears to be sensitive to low-frequency sounds, but its hearing limit is relatively high. The presence of a well-developed tympanal recess links Caperea with cetotheriids and balaenopteroids, rather than balaenids, contrary to the traditional morphological view of a close Caperea-balaenid relationship. Nevertheless, a broader s le of the cetotheriid Herpetocetus demonstrates that the presence of a tympanal recess can be variable at the specific and possibly even the intraspecific level.

The pre-Pleistocene fossil thylacinids (Dasyuromorphia: Thylacinidae) and the evolutionary context of the modern thylacine

Publisher: PeerJ

Date: 02-09-2019

DOI: 10.7717/PEERJ.7457

Abstract: The thylacine is popularly used as a classic ex le of convergent evolution between placental and marsupial mammals. Despite having a fossil history spanning over 20 million years and known since the 1960s, the thylacine is often presented in both scientific literature and popular culture as an evolutionary singleton unique in its morphological and ecological adaptations within the Australian ecosystem. Here, we synthesise and critically evaluate the current state of published knowledge regarding the known fossil record of Thylacinidae prior to the appearance of the modern species. We also present phylogenetic analyses and body mass estimates of the thylacinids to reveal trends in the evolution of hypercarnivory and ecological shifts within the family. We find support that Mutpuracinus archibaldi occupies an uncertain position outside of Thylacinidae, and consider Nimbacinus richi to likely be synonymous with N. dicksoni . The Thylacinidae were small-bodied ( ~8 kg) unspecialised faunivores until after the ~15–14 Ma middle Miocene climatic transition (MMCT). After the MMCT they dramatically increase in size and develop adaptations to a hypercarnivorous diet, potentially in response to the aridification of the Australian environment and the concomitant radiation of dasyurids. This fossil history of the thylacinids provides a foundation for understanding the ecology of the modern thylacine. It provides a framework for future studies of the evolution of hypercarnivory, cursoriality, morphological and ecological disparity, and convergence within mammalian carnivores.

Skull shape reflects prey size niche in toothed whales

Publisher: Oxford University Press (OUP)

Date: 10-05-2017

DOI: 10.1093/BIOLINNEAN/BLX032

New small-bodied ornithopods (Dinosauria, Neornithischia) from the Early Cretaceous Wonthaggi Formation (Strzelecki Group) of the Australian-Antarctic rift system, with revision of Qantassaurus intrepidus Rich and Vickers-Rich, 1999

Publisher: Cambridge University Press (CUP)

Date: 11-03-2019

DOI: 10.1017/JPA.2018.95

Abstract: The Flat Rocks locality in the Wonthaggi Formation (Strzelecki Group) of the Gippsland Basin, southeastern Australia, hosts fossils of a late Barremian vertebrate fauna that inhabited the ancient rift between Australia and Antarctica. Known from its dentary, Qantassaurus intrepidus Rich and Vickers-Rich, 1999 has been the only dinosaur named from this locality. However, the plethora of vertebrate fossils collected from Flat Rocks suggests that further dinosaurs await discovery. From this locality, we name a new small-bodied ornithopod, Galleonosaurus dorisae n. gen. n. sp. from craniodental remains. Five ornithopodan genera are now named from Victoria. Galleonosaurus dorisae n. gen. n. sp. is known from five maxillae, from which the first description of jaw growth in an Australian dinosaur is provided. The holotype of Galleonosaurus dorisae n. gen. n. sp. is the most complete dinosaur maxilla known from Victoria. Micro-CT imagery of the holotype reveals the complex internal anatomy of the neurovascular tract and antorbital fossa. We confirm that Q. intrepidus is uniquely characterized by a deep foreshortened dentary. Two dentaries originally referred to Q. intrepidus are reassigned to Q. ? intrepidus and a further maxilla is referred to cf. Atlascopcosaurus loadsi Rich and Rich, 1989. A further ornithopod dentary morphotype is identified, more elongate than those of Q. intrepidus and Q. ? intrepidus and with three more tooth positions. This dentary might pertain to Galleonosaurus dorisae n. gen. n. sp. Phylogenetic analysis recovered Cretaceous Victorian and Argentinian nonstyracosternan ornithopods within the exclusively Gondwanan clade Elasmaria. However, the large-bodied taxon Muttaburrasaurus langdoni Bartholomai and Molnar, 1981 is hypothesised as a basal iguanodontian with closer affinities to dryomorphans than to rhabdodontids. UUID: af87bb4-b687-42f3-9622-aa806a6b4116

Lopinavir-ritonavir and hydroxychloroquine for critically ill patients with COVID-19: REMAP-CAP randomized controlled trial

Publisher: Springer Science and Business Media LLC

Date: 12-07-2021

DOI: 10.1007/S00134-021-06448-5

The extraordinary osteology and functional morphology of the limbs in Palorchestidae, a family of strange extinct marsupial giants

Publisher: Public Library of Science (PLoS)

Date: 13-09-2019

DOI: 10.1371/JOURNAL.PONE.0221824

Sharp and fully loaded: 3D tissue reconstruction reveals how snake fangs stay deadly during fang replacement

Publisher: Wiley

Date: 03-08-2021

DOI: 10.1111/JOA.13531

Abstract: Snake venom is produced, transported and delivered by the sophisticated venom delivery system (VDS). When snakes bite, the venom travels from the venom gland through the venom duct into needle‐like fangs that inject it into their prey. To counteract breakages, fangs are continuously replaced throughout life. Currently, the anatomy of the connection between the duct and the fang has not been described, and the mechanism by which the duct is reconnected to the replacement fang has not been identified. We examined the VDS in 3D in representative species from two families and one subfamily (Elapidae, Viperidae, Atractaspidinae) using contrast‐enhanced microCT (diceCT), followed by dissection and histology. We observed that the venom duct bifurcates immediately anterior to the fangs so that both the original and replacement fangs are separately connected and functional in delivering venom. When a fang is absent, the canal leading to the empty position is temporarily closed. We found that elapid snakes have a crescent‐shaped venom reservoir where venom likely pools before it enters the fang. These findings form the final piece of the puzzle of VDS anatomy in front‐fanged venomous snakes. Additionally, they provide further evidence for independent evolution of the VDS in these three snake taxa.

3D Morphometric Analysis Reveals Similar Ecomorphs for Early Kangaroos (Macropodidae) and Fanged Kangaroos (Balbaridae) from the Riversleigh World Heritage Area, Australia

Publisher: Springer Science and Business Media LLC

Date: 11-06-2020

DOI: 10.1007/S10914-020-09507-8

Rational clinical pathology assessment in the intensive care unit

Publisher: SAGE Publications

Date: 07-2017

DOI: 10.1177/0310057X1704500415

Abstract: Blood tests are ordered on a daily basis in intensive care units (ICU). There are no widely accepted guidelines for testing requirements. This study investigated the impact on ICU laboratory test costs of a multi-strategy change in practice involving routine blood testing. A single centre, prospective, interventional study using historical controls was undertaken to investigate the impact of ICU specialist authorisation of high-volume routine tests on ICU laboratory test costs. Prior to commencement of the study, ICU nursing and junior ICU doctors were able to order tests. During the six-month intervention period, the ICU specialists authorised routine blood tests. Adverse events related to not performing blood tests were also recorded. Overall ICU laboratory test costs decreased by 12.3% over the six months (P=0.0022 versus historical control) with a mean compliance of 51% with the test authorisation protocol. The costs of frequently ordered tests (classified as high-volume) decreased by 20% (P=0.0022 versus historical control). These accounted for an average of 54 ± 3% of the overall ICU blood test costs (blood gas analyses 17%, simple chemistry tests consisting of electrolytes, liver function, calcium, phosphate, magnesium 14%, coagulation 12% and full blood count 11%). Two protocol-related adverse events were recorded and judged as minor and were resolved by ordering tests during the day. No adverse patient outcomes resulted from these two events. Blood testing authorisation by an ICU specialist was associated with significant cost savings in ICU and no adverse patient outcomes.

A simple rule governs the evolution and development of hominin tooth size

Publisher: Springer Science and Business Media LLC

Date: 02-2016

DOI: 10.1038/NATURE16972

Abstract: The variation in molar tooth size in humans and our closest relatives (hominins) has strongly influenced our view of human evolution. The reduction in overall size and disproportionate decrease in third molar size have been noted for over a century, and have been attributed to reduced selection for large dentitions owing to changes in diet or the acquisition of cooking. The systematic pattern of size variation along the tooth row has been described as a 'morphogenetic gradient' in mammal, and more specifically hominin, teeth since Butler and Dahlberg. However, the underlying controls of tooth size have not been well understood, with hypotheses ranging from morphogenetic fields to the clone theory. In this study we address the following question: are there rules that govern how hominin tooth size evolves? Here we propose that the inhibitory cascade, an activator-inhibitor mechanism that affects relative tooth size in mammals, produces the default pattern of tooth sizes for all lower primary postcanine teeth (deciduous premolars and permanent molars) in hominins. This configuration is also equivalent to a morphogenetic gradient, finally pointing to a mechanism that can generate this gradient. The pattern of tooth size remains constant with absolute size in australopiths (including Ardipithecus, Australopithecus and Paranthropus). However, in species of Homo, including modern humans, there is a tight link between tooth proportions and absolute size such that a single developmental parameter can explain both the relative and absolute sizes of primary postcanine teeth. On the basis of the relationship of inhibitory cascade patterning with size, we can use the size at one tooth position to predict the sizes of the remaining four primary postcanine teeth in the row for hominins. Our study provides a development-based expectation to examine the evolution of the unique proportions of human teeth.

Environmental sustainability in the intensive care unit

Publisher: Elsevier BV

Date: 06-2023

DOI: 10.1016/J.CCRJ.2023.04.001

Ornithopod jaws from the Lower Cretaceous Eumeralla Formation, Victoria, Australia, and their implications for polar neornithischian dinosaur diversity

Publisher: Informa UK Limited

Date: 04-05-2021

DOI: 10.1080/02724634.2021.1946551

Tocilizumab for severe COVID-19 pneumonia

Publisher: Wiley

Date: 08-2020

DOI: 10.1111/1756-185X.13913

A farewell to arms and legs: a review of limb reduction in squamates

Publisher: Wiley

Date: 03-02-2021

DOI: 10.1111/BRV.12690

Prey capture and processing behaviors vary with prey size and shape in Australian and subantarctic fur seals

Publisher: Wiley

Date: 09-12-2016

DOI: 10.1111/MMS.12285

Clawed forelimbs allow northern seals to eat like their ancient ancestors

Publisher: The Royal Society

Date: 04-2018

DOI: 10.1098/RSOS.172393

Abstract: Streamlined flippers are often considered the defining feature of seals and sea lions, whose very name ‘pinniped’ comes from the Latin pinna and pedis , meaning ‘fin-footed’. Yet not all pinniped limbs are alike. Whereas otariids (fur seals and sea lions) possess stiff streamlined forelimb flippers, phocine seals (northern true seals) have retained a webbed yet mobile paw bearing sharp claws. Here, we show that captive and wild phocines routinely use these claws to secure prey during processing, enabling seals to tear large fish by stretching them between their teeth and forelimbs. ‘Hold and tear’ processing relies on the primitive forelimb anatomy displayed by phocines, which is also found in the early fossil pinniped Enaliarctos . Phocine forelimb anatomy and behaviour therefore provide a glimpse into how the earliest seals likely fed, and indicate what behaviours may have assisted pinnipeds along their journey from terrestrial to aquatic feeding.

The Tympanal Recess of the Cetacean Cochlea

Publisher: Springer Science and Business Media LLC

Date: 08-2017

DOI: 10.1007/S40857-017-0104-9

Frailty, delirium and hospital mortality of older adults admitted to intensive care: the Delirium (Deli) in ICU study

Publisher: Springer Science and Business Media LLC

Date: 15-10-2020

DOI: 10.1186/S13054-020-03318-2

Abstract: Clinical frailty among older adults admitted to intensive care has been proposed as an important determinant of patient outcomes. Among this group of patients, an acute episode of delirium is also common, but its relationship to frailty and increased risk of mortality has not been extensively explored. Therefore, the aim of this study was to explore the relationship between clinical frailty, delirium and hospital mortality of older adults admitted to intensive care. This study is part of a Delirium in Intensive Care (Deli) Study. During the initial 6-month baseline period, clinical frailty status on admission to intensive care, among adults aged 50 years or more acute episodes of delirium and the outcomes of intensive care and hospital stay were explored. During the 6-month baseline period, 997 patients, aged 50 years or more, were included in this study. The average age was 71 years (IQR, 63–79) 55% were male ( n = 537). Among these patients, 39.2% (95% CI 36.1–42.3%, n = 396) had a Clinical Frailty Score (CFS) of 5 or more, and 13.0% ( n = 127) had at least one acute episode of delirium. Frail patients were at greater risk of an episode of delirium (17% versus 10%, adjusted rate ratio ( adj RR) = 1.71, 95% confidence interval (CI) 1.20–2.43, p = 0.003), had a longer hospital stay (2.6 days, 95% CI 1–7 days, p = 0.009) and had a higher risk of hospital mortality (19% versus 7%, adj RR = 2.54, 95% CI 1.72–3.75, p 0.001), when compared to non-frail patients. Patients who were frail and experienced an acute episode of delirium in the intensive care had a 35% rate of hospital mortality versus 10% among non-frail patients who also experienced delirium in the ICU. Frailty and delirium significantly increase the risk of hospital mortality. Therefore, it is important to identify patients who are frail and institute measures to reduce the risk of adverse events in the ICU such as delirium and, importantly, to discuss these issues in an open and empathetic way with the patient and their families.

The maximum rate of mammal evolution

Publisher: Proceedings of the National Academy of Sciences

Date: 30-01-2012

DOI: 10.1073/PNAS.1120774109

Abstract: How fast can a mammal evolve from the size of a mouse to the size of an elephant? Achieving such a large transformation calls for major biological reorganization. Thus, the speed at which this occurs has important implications for extensive faunal changes, including adaptive radiations and recovery from mass extinctions. To quantify the pace of large-scale evolution we developed a metric, clade maximum rate, which represents the maximum evolutionary rate of a trait within a clade. We applied this metric to body mass evolution in mammals over the last 70 million years, during which multiple large evolutionary transitions occurred in oceans and on continents and islands. Our computations suggest that it took a minimum of 1.6, 5.1, and 10 million generations for terrestrial mammal mass to increase 100-, and 1,000-, and 5,000-fold, respectively. Values for whales were down to half the length (i.e., 1.1, 3, and 5 million generations), perhaps due to the reduced mechanical constraints of living in an aquatic environment. When differences in generation time are considered, we find an exponential increase in maximum mammal body mass during the 35 million years following the Cretaceous–Paleogene (K–Pg) extinction event. Our results also indicate a basic asymmetry in macroevolution: very large decreases (such as extreme insular dwarfism) can happen at more than 10 times the rate of increases. Our findings allow more rigorous comparisons of microevolutionary and macroevolutionary patterns and processes.

Correction to: First monk seal from the Southern Hemisphere rewrites the evolutionary history of true seals

Publisher: The Royal Society

Date: 08-09-2021

DOI: 10.1098/RSPB.2021.1858

Convergent Traits in Mammals Associated with Divergent Behaviors: the Case of the Continuous Dental Replacement in Rock-Wallabies and African Mole-Rats

Publisher: Springer Science and Business Media LLC

Date: 25-08-2016

DOI: 10.1007/S10914-016-9348-7

COVID-19 associated pulmonary aspergillosis (CAPA): An Australian case report

Publisher: Elsevier BV

Date: 03-2021

DOI: 10.1016/J.MMCR.2020.06.002

Eye in the sky: observing wild dingo hunting behaviour using drones

Publisher: CSIRO Publishing

Date: 16-12-2022

DOI: 10.1071/WR22033

Abstract: Context The behaviours used by mammalian predators to track, kill, and consume prey are some of the most dynamic interspecific interactions in nature. However, they are often challenging to follow through the landscape and observe directly without disturbing the animals being watched. Aims We describe the behaviours used by wild dingoes while hunting macropods in Namadgi National Park, Australian Capital Territory, Australia. Methods Footage was initially captured by wildlife cinematographers on behalf of documentary programs and was made available for viewing after production. Hunting events were filmed from an altitude of m by using a ‘long lens’ fitted to either a drone or helicopter. Results We recorded a suite of hunting behaviours that would have been extremely challenging to observe from the ground via traditional methods. This includes some of the first video records published in the scientific literature of the behaviours used by dingoes to hunt and kill macropod prey, as well as some rare observations of mother and pup hunting dynamics. We did not observe any signs of disturbance as a result of filming for either predator or prey. Conclusions The varied repertoire of predatory behaviours displayed by dingoes is similar to that documented in wolves and asserts them as a behaviourally complex top predator in the Australian landscape. In addition, we highlight the use of drones as a valuable approach for directly observing wild behaviours. They offer a minimally invasive and relatively inexpensive and accessible alternative to helicopters. This project is also a case study exemplifying the value of collaborations between filmmakers and researchers that enable the sharing of archival documentary footage for the study of wild animal behaviour. Implications Future studies of wild animal behaviour should consider employing drones (at a safe distance and in accordance with published best practices and guidelines) as an additional tool to collect types of data that would be challenging using other methods.

Mouthpart morphology and trophic position of microarthropods from soils and mosses are strongly correlated

Publisher: Elsevier BV

Date: 10-2012

DOI: 10.1016/J.SOILBIO.2012.05.002

Evidence of Dietary Differentiation Among Late Paleocene-Early Eocene Plesiadapids (Mammalia, Primates)

Publisher: Wiley

Date: 2010

DOI: 10.1002/AJPA.21211

Abstract: Plesiadapis cookei is an extinct relative of extant euarchontans (primates, dermopterans scandentians), which lived in North America during the late Paleocene. P. cookei body mass has been estimated to be approximately 2.2 kg, making it large compared with other species of its genus from North America, but similar to some from Europe. In particular, size as well as dental form similarities to P. russelli have been noted. However, it is thought that P. russelli evolved from P. tricuspidens, and into Platychoerops daubrei. Dental similarities among P. cookei, P. russelli, and P. daubrei have been hypothesized to reflect a more folivorous diet than utilized by P. tricuspidens. Here we test the hypothesis that P. cookei is more dietarily specialized than P. tricuspidens by quantifying functionally significant aspects of molar, premolar, and incisor forms. Casts of M(2)s and P(4)s of P. tricuspidens, P. cookei, and P. daubrei were microCT-scanned. We measured the relief index and/or the complexity from surface reconstructions of scans. Results show that P. cookei has higher M(2) relief and complexity than P. tricuspidens P. daubrei exhibits the highest relief and complexity. Similarly, P. cookei has a more complex P(4) than P. tricuspidens, whereas that of P. daubrei exhibits the highest complexity. Finally, the I(1) of P. cookei resembles more the incisor of P. daubrei than that of P. tricuspidens. Because high relief and complexity of dentitions are related to fibrous plant diets in living mammals, these findings support the hypothesis that previously identified similarities among P. cookei, P. russelli and P. daubrei reflect a folivorous diet.

A database of the morphology, ecology and literature of the world's limb‐reduced skinks

Publisher: Wiley

Date: 18-05-2022

DOI: 10.1111/JBI.14392

Abstract: Limb‐reduced squamates are a convenient model system to investigate macroevolutionary trends in morphology. Here, we provide morphological, ecological and literature data on all known species of limb‐reduced skinks (Scincidae) and their relatives, representing one of the most erse and widely distributed groups of limb‐reduced squamates. Global. Skinks (Reptilia, Squamata: Scincidae). Limb‐reduced forms. Morphological data were sourced from the primary literature, spanning a period of over 150 years. Linear body measurements were averaged across all values in the literature, preserving proportionality to body length. For digits and presacral vertebrae, we used maximum recorded counts. Ecological and biogeographical data were sourced from habitat assessments in the primary literature, online databases and field guides. Literature data were sorted according to type of study. To exemplify the applicability of the database, we used Markov‐chain ordered models to estimate the evolutionary frequency of limb reduction and loss in skinks. We find evidence of limb reduction and loss in a total of 394 species worldwide, representing ~23% of all skink species, and ~30% of genera. The distribution of limb‐reduced and limbless forms differs from that of fully limbed forms, as they are present in all biogeographic realms with the almost complete exclusion of the Americas. We estimate that limb reduction evolved more than 50 times in skinks, and that loss of at least one limb pair evolved at least 24 times. The dataset captures a broad spectrum of morphological and ecological variation in a large, globally distributed taxonomic group. It establishes a widely applicable definition of limb reduction based on limb proportions as a reference for future studies. Such an extensive collection of morphological and ecological data can pave the way for investigations of dramatic morphological transitions and their ecological drivers at a global and local scale.

Functional constraints on tooth morphology in carnivorous mammals

Publisher: Springer Science and Business Media LLC

Date: 2012

DOI: 10.1186/1471-2148-12-146

Inferring the palaeobiology of palorchestid marsupials through analysis of mammalian humeral and femoral shape

Publisher: Springer Science and Business Media LLC

Date: 23-12-2023

DOI: 10.1007/S10914-022-09640-6

Biomechanical properties of insects in relation to insectivory: cuticle thickness as an indicator of insect 'hardness' and 'intractability'

Publisher: CSIRO Publishing

Date: 2005

DOI: 10.1071/ZO04018

Abstract: The concept of ‘hardness’ has long been used to describe the biomechanical properties of the diet of many animals. However, due to the lack of a consistent definition, and the multitude of uses to which the term has been put, the use of the term ‘intractability’ has been advocated here to represent the extent to which the structural strength, stiffness and toughness are increased in a foodstuff. The thickness of the cuticle of an insect was a good measure of the intractability of cuticle. The tremendous advantage of the use of cuticle thickness as a measure of the biomechanical properties of invertebrates means that the dietary properties of a living insectivore can be directly quantified according to the thickness of the cuticle in its faeces. The quantitative measurement of intractability obtained through this technique can be used in correlations with adaptations of the masticatory apparatus, including tooth and skull morphology, as well as more general considerations of ecology. This is a major advance on previous measures of the biomechanical properties of insectivore diets, and may represent the best technique of any dietary group in assessing the properties of its diet.

Worldwide Organization of Neurocritical Care: Results from the PRINCE Study Part 1

Publisher: Springer Science and Business Media LLC

Date: 07-06-2019

DOI: 10.1007/S12028-019-00750-3

Calorie intake and patient outcomes in severe acute kidney injury: findings from The Randomized Evaluation of Normal vs. Augmented Level of Replacement Therapy (RENAL) study trial

Publisher: Springer Science and Business Media LLC

Date: 2014

DOI: 10.1186/CC13767

Inferring mammal dietary ecology from dental morphology

Publisher: Springer International Publishing

Date: 2018

DOI: 10.1007/978-3-319-94265-0_4

Australian fur seals (Arctocephalus pusillus doriferus) use raptorial biting and suction feeding when targeting prey in different foraging scenarios

Publisher: Public Library of Science (PLoS)

Date: 12-11-2014

DOI: 10.1371/JOURNAL.PONE.0112521

Low-frequency hearing preceded the evolution of giant body size and filter feeding in baleen whales

Publisher: The Royal Society

Date: 08-02-2017

DOI: 10.1098/RSPB.2016.2528

Abstract: Living baleen whales (mysticetes) produce and hear the lowest-frequency (infrasonic) sounds among mammals. There is currently debate over whether the ancestor of crown cetaceans (Neoceti) was able to detect low frequencies. However, the lack of information on the most archaic fossil mysticetes has prevented us from determining the earliest evolution of their extreme acoustic biology. Here, we report the first anatomical analyses and frequency range estimation of the inner ear in Oligocene (34–23 Ma) fossils of archaic toothed mysticetes from Australia and the USA. The cochlear anatomy of these small fossil mysticetes resembles basilosaurid archaeocetes, but is also similar to that of today's baleen whales, indicating that even the earliest mysticetes detected low-frequency sounds, and lacked ultrasonic hearing and echolocation. This suggests that, in contrast to recent research, the plesiomorphic hearing condition for Neoceti was low frequency, which was retained by toothed mysticetes, and the high-frequency hearing of odontocetes is derived. Therefore, the low-frequency hearing of baleen whales has remained relatively unchanged over the last approximately 34 Myr, being present before the evolution of other signature mysticete traits, including filter feeding, baleen and giant body size.

Ancient whales did not filter feed with their teeth

Publisher: The Royal Society

Date: 08-2017

DOI: 10.1098/RSBL.2017.0348

Abstract: The origin of baleen whales (Mysticeti), the largest animals on Earth, is closely tied to their signature filter-feeding strategy. Unlike their modern relatives, archaic whales possessed a well-developed, heterodont adult dentition. How these teeth were used, and what role their function and subsequent loss played in the emergence of filter feeding, is an enduring mystery. In particular, it has been suggested that elaborate tooth crowns may have enabled stem mysticetes to filter with their postcanine teeth in a manner analogous to living crabeater and leopard seals, thereby facilitating the transition to baleen-assisted filtering. Here we show that the teeth of archaic mysticetes are as sharp as those of terrestrial carnivorans, raptorial pinnipeds and archaeocetes, and thus were capable of capturing and processing prey. By contrast, the postcanine teeth of leopard and crabeater seals are markedly blunter, and clearly unsuited to raptorial feeding. Our results suggest that mysticetes never passed through a tooth-based filtration phase, and that the use of teeth and baleen in early whales was not functionally connected. Continued selection for tooth sharpness in archaic mysticetes is best explained by a feeding strategy that included both biting and suction, similar to that of most living pinnipeds and, probably, early toothed whales (Odontoceti).

Multiple hypotheses about two mammalian upper dentitions from the Early Cretaceous of Australia

Publisher: Informa UK Limited

Date: 10-2020

DOI: 10.1080/03115518.2020.1829042

The sensitivity of biological finite element models to the resolution of surface geometry: a case study of crocodilian crania

Publisher: PeerJ

Date: 02-06-2015

DOI: 10.7717/PEERJ.988

Convergent evolution of forelimb-propelled swimming in seals

Publisher: Elsevier BV

Date: 06-2021

DOI: 10.1016/J.CUB.2021.03.019

Abstract: Modern pinnipeds (true and eared seals) employ two radically different swimming styles, with true seals (phocids) propelling themselves primarily with their hindlimbs, whereas eared seals (otariids) rely on their wing-like foreflippers.

Rhinocerotidae

Publisher: Springer Netherlands

Date: 07-12-2011

DOI: 10.1007/978-90-481-9962-4_11

Low elbow mobility indicates unique forelimb posture and function in a giant extinct marsupial

Publisher: Wiley

Date: 02-02-2021

DOI: 10.1111/JOA.13389

Abstract: Joint mobility is a key factor in determining the functional capacity of tetrapod limbs, and is important in palaeobiological reconstructions of extinct animals. Recent advances have been made in quantifying osteological joint mobility using virtual computational methods however, these approaches generally focus on the proximal limb joints and have seldom been applied to fossil mammals. Palorchestes azael is an enigmatic, extinct ~1000 kg marsupial with no close living relatives, whose functional ecology within Australian Pleistocene environments is poorly understood. Most intriguing is its flattened elbow morphology, which has long been assumed to indicate very low mobility at this important joint. Here, we tested elbow mobility via virtual range of motion (ROM) mapping and helical axis analysis, to quantitatively explore the limits of Palorchestes ' elbow movement and compare this with their living and extinct relatives, as well as extant mammals that may represent functional analogues. We find that Palorchestes had the lowest elbow mobility among mammals s led, even when afforded joint translations in addition to rotational degrees of freedom. This indicates that Palorchestes was limited to crouched forelimb postures, something highly unusual for mammals of this size. Coupled flexion and abduction created a skewed primary axis of movement at the elbow, suggesting an abducted forelimb posture and humeral rotation gait that is not found among marsupials and unlike that seen in any large mammals alive today. This work introduces new quantitative methods and demonstrates the utility of comparative ROM mapping approaches, highlighting that Palorchestes ' forelimb function was unlike its contemporaneous relatives and appears to lack clear functional analogues among living mammals.

Feeding Ecology and Morphology Make a Bamboo Specialist Vulnerable to Climate Change

Publisher: Elsevier BV

Date: 11-2017

DOI: 10.1016/J.CUB.2017.09.050

Abstract: Animals with dietary specializations can be used to link climate to specific ecological drivers of endangerment. Only two mammals, the giant panda (Ailuropoda melanoleuca) in Asia and the greater bamboo lemur (Prolemur simus) in Madagascar, consume the nutritionally poor and mechanically challenging culm or trunk of woody bamboos [1-3]. Even though the greater bamboo lemur is critically endangered, paleontological evidence shows that it was once broadly distributed [4, 5]. Here, integrating morphological, paleontological, and ecological evidence, we project the effects of climate change on greater bamboo lemurs. Both the giant panda and the greater bamboo lemur are shown to share diagnostic dental features indicative of a bamboo diet, thereby providing an ecometric indicator [6, 7] of diet preserved in the fossil record. Analyses of bamboo feeding in living populations show that bamboo culm is consumed only during the dry season and that the greater bamboo lemur is currently found in regions with the shortest dry season. In contrast, paleontological localities of the greater bamboo lemurs have the longest dry seasons. Future projections show that many present-day greater bamboo lemur populations will experience prolonged dry seasons similar to those of the localities where only fossils of the greater bamboo lemur are found. Whereas abundant foods such as bamboo allow feeding specialists to thrive, even a moderate change in seasonality may outstrip the capacity of greater bamboo lemurs to persist on their mechanically demanding food source. Coupling known changes in species distribution with high-resolution ecological and historical data helps to identify extinction risks.

Did the thylacine violate the costs of carnivory? Body mass and sexual dimorphism of an iconic Australian marsupial

Publisher: The Royal Society

Date: 19-08-2020

DOI: 10.1098/RSPB.2020.1537

Abstract: The relative body masses of predators and their prey strongly affect the predators' ecology. An accurate estimate of the mass of an extinct predator is therefore key to revealing its biology and the structure of the ecosystem it inhabited. Until its extinction, the thylacine was the largest extant carnivorous marsupial, but little data exist regarding its body mass, with an average of 29.5 kg the most commonly used estimate. According to the costs of carnivory model, this estimate predicts that thylacines would have focused on prey subequal to or larger than themselves however, many studies of their functional morphology suggest a diet of smaller animals. Here, we present new body mass estimates for 93 adult thylacines, including two taxidermy specimens and four complete mounted skeletons, representing 40 known-sex specimens, using three-dimensional volumetric model-informed regressions. We demonstrate that prior estimates substantially overestimated average adult thylacine body mass. We show mixed-sex population mean (16.7 kg), mean male (19.7 kg), and mean female (13.7 kg) body masses well below prior estimates, and below the 21 kg costs of carnivory threshold. Our data show that the thylacine did not violate the costs of carnivory. The thylacine instead occupied the 14.5–21 kg predator rey range characterized by small-prey predators capable of occasionally switching to relatively large-bodied prey if necessary.

Foraging-based enrichment promotes more varied behaviour in captive Australian fur seals (Arctocephalus pusillus doriferus)

Publisher: Public Library of Science (PLoS)

Date: 06-05-2015

DOI: 10.1371/JOURNAL.PONE.0124615

Monash University

Location: Australia

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Linkage Projects - Grant ID: LP150100403

Start Date: 02-2016

End Date: 12-2019

Amount: $421,765.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP110100726

Start Date: 07-2011

End Date: 12-2014

Amount: $285,000.00

Funder: Australian Research Council

ARC Future Fellowships - Grant ID: FT130100968

Start Date: 12-2013

End Date: 12-2019

Amount: $739,168.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP180101797

Start Date: 07-2018

End Date: 09-2023

Amount: $422,080.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP230100613

Start Date: 10-2023

End Date: 10-2026

Amount: $467,058.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP170100012

Start Date: 10-2018

End Date: 09-2022

Amount: $300,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP0880120

Start Date: 07-2008

End Date: 06-2013

Amount: $600,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE130100115

Start Date: 2013

End Date: 12-2013

Amount: $180,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE130100006

Start Date: 2013

End Date: 12-2013

Amount: $500,000.00

Funder: Australian Research Council