SREL Reprint #2447

Life history evolution and adaptive radiation of hemidactyliine salamanders

Travis J. Ryan1,2 and Richard C. Bruce3

1Savannah River Ecology Laboratory, Drawer E, Aiken, South Carolina 29802
2Division of Biological Sciences, University of Missouri, Columbia, Missouri 65211
3Department of Biology, Western Carolina University, Cullowhee, North Carolina 28723

Introduction: The tribe Hemidactyliini (Caudata: Plethodontidae: Plethodontinae) is a morphologically conservative taxon, comprising about 25 species distributed over eight genera (Conant and Collins, 1998). Despite significant attention over the last 30 years, there are many problems regarding the phylogeny and taxonomy of the Hemidactyliini. Wake (1966, 1993) has questioned the monophyly of this group, and recent phylogenetic analyses have failed to resolve the question (e.g., Rose, 1995; Sever, 1994). Hemidactyliines are relatively generalized salamanders, lacking the degree of morphological specialization found in the other three plethodontid lineages; e.g., the skeletomuscular adaptations for feeding and burrowing of the desmognathines (Schwenk and Wake, 1993), the specializations of the tongue projection mechanism of bolitoglossines (Deban et al., 1997; Lombard and Wake, 1977), and the derived morphogenetic features associated with direct development in both bolitoglossines and plethodontines (Collazo and Marks, 1994). Furthermore, all hemidactyliines have a larval stage and the majority exhibit a complex life cycle (Wilbur, 1980), and thus differ from the other members of the subfamily Plethodontinae, their closest relatives. A complex life cycle is considered ancestral for the family Plethodontidae and is shared with most members of the subfamily Desmognathinae (Wake, 1966). . . .

SREL Reprint #2447

Ryan, T. J., and R. C. Bruce. 2000. Life history evolution and adaptive radiation of hemidactyliine salamanders. pp. 303-326 In: Bruce et al. (Eds.). Biology of Plethodontid Salamanders. Plenum Publishers, New York.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).