Meeting Abstract

53.4  Tuesday, Jan. 5  Comparative Skull Morphology of Karsenia koreana (Amphibia, Caudata, Plethodontidae) BUCKLEY, David; WAKE, Marvalee H.; WAKE, David B.*; Univ. of California, Berkeley; Univ. of California, Berkeley; Univ. of California, Berkeley wakelab@berkeley.edu

Karsenia koreana is the only Asiatic representative of the salamander family Plethodontidae. Its recent discovery challenged our understanding of the biogeographic history of the family, which otherwise is distributed in the New World with a few European species. Molecular studies suggest that Karsenia forms a clade with Hydromantes (sensu lato) , which includes among its species the only other Old World plethodontids. Morphologically, Karsenia closely resembles Plethodon. We studied the skull of K. koreana and compared it to that of other plethodontines. No clearly autapomorphic states were detected, and no synapomorphies can be found that would link it to other genera. The Karsenia skull is cylindrical and well ossified, giving an impression of strength. In contrast, the skull of Hydromantes is highly derived; the skull is flattened and the bones are weakly ossified and articulated. Hydromantes and Karsenia share no unique anatomical features; differences between them are especially evident in the hyobranchial skeleton, which is generalized in Karsenia but highly modified in Hydromantes, a clade well-known for its highly projectile tongue. Plethodon and Plethodon-like species, including Karsenia and to a lesser degree Ensatina, represent the more generalized and apparently ancestral plethodontid morphology. Specialized morphologies in plethodontids have evolved along only a few morphological axes, resulting in a pattern of rampant homoplasy. Our analysis of the anatomy of the new Asiatic lineage illuminates some potential mechanisms underlying adaptive morphological evolution within the Plethodontidae. Research supported by NSF AmphibiaTree program (EF-0334939).