Publication
Discovery of a new family of amphibians from northeast India with ancient links to Africa
Publisher:
The Royal Society
Date:
22-02-2012
DOI:
10.1098/RSPB.2012.0150
Abstract: The limbless, primarily soil-dwelling and tropical caecilian hibians (Gymnophiona) comprise the least known order of tetrapods. On the basis of unprecedented extensive fieldwork, we report the discovery of a previously overlooked, ancient lineage and radiation of caecilians from threatened habitats in the underexplored states of northeast India. Molecular phylogenetic analyses of mitogenomic and nuclear DNA sequences, and comparative cranial anatomy indicate an unexpected sister-group relationship with the exclusively African family Herpelidae. Relaxed molecular clock analyses indicate that these lineages erged in the Early Cretaceous, about 140 Ma. The discovery adds a major branch to the hibian tree of life and sheds light on both the evolution and biogeography of caecilians and the biotic history of northeast India—an area generally interpreted as a gateway between bio ersity hotspots rather than a distinct biogeographic unit with its own ancient endemics. Because of its distinctive morphology, inferred age and phylogenetic relationships, we recognize the newly discovered caecilian radiation as a new family of modern hibians.