Evolution of Pipoid Frogs: Morphology and Phylogenetic Relationships of Pseudhymenochirus

Publisher Website
Google Scholar
Abstract
The phylogenetic relationships of the poorly known African pipid frog Pseudhymenochirus merlini were studied using phylogenetic analysis of comparative morphology. Forty-nine characters from fourteen species were surveyed from integumentary structures, osteology (especially of the cranium and pectoral girdle), and larvae. The resultant cladogram is well corroborated; only six of the characters exhibited homoplasy. Pseudhymenochirus is not merely a primitive Hymenochirus, nor is it an intermediate between Xenopus and Hymenochirus. It is the sister-group to Hymenochirus (boettgeri and curtipes) and possesses several derived features not found in other pipids. Pseudhymenochirus and Hymenochirus together (the hymenochirines) are the sister-group to Pipa; the three genera are included in the subfamily Pipinae. Several of the unique features in hymenochirines may be related to the small size of these animals.