Phylogenetic Hypotheses for the Evolution of Modern Kinosternine Turtles

Abstract

Cladograms of kinosternine turtles were generated based on a phylogenetic analysis of the distribution of character states within 27 morphological characters. These cladograms were compared to those of Seidel et al. (1986), which were based on binary coding of 34 protein electromorph products, those based on multistate coding of the presumptive loci responsible for those products, and those based on the combined protein and morphology data sets. The analyses resolve the relationships of most kinosternine taxa very well, with taxa with small plastrons generally being the most primitive, and those with large plastrons being the most derived. However, the morphologic data set may be biased because of character redundance, in this case due to high correlation of at least 16 of the characters with relative plastron size. The two remaining controversies concern the monophyly of the genus Sternotherus (here considered a subgenus of Kinosternon) and the determination of the nearest relatives of K. leucostomum.