ALBRIGHT, G.; SUMIDA, S.S.; DODICK, J.: The Basal Reptilian Family Captorhinidae and Basal Amniote Interrelationships

Phylogenetic analyses during the past two decades have shown the Late Paleozoic Captorhinidae to be amongst the most basal of eureptilians. A re-analysis of the intrafamilial relationships of the Captorhinidae is combined with: (1) phylogenetic analyses of the Diadectomorpha, acknowledged to be the sistergroup of Amniota, (2) the well-understood interrelationships of basal Synapsida, and (3) recent description of Eudibamus cursoris, the earliest known facultative biped and member of the parareptilian Bolosauridae. Combining these data provides a more clearly resolved understanding of the interrelationships of basal amniotes. Within the Amniota, basal captorhinids may now be characterized more clearly as well. Description of a new species of captorhinid reptile and re-analysis of captorhinid relationships indicates that this predominantly Early Permian family demonstrates marked similarities is size distribution to certain extant families of lizards. Although morphology through the family is fairly conservative, large size appears to have evolved at least two, and possibly three times. The family exhibits a small number of taxa that are significantly larger than the common and average size, and at least one “miniaturized” taxon, Captorhinikos parvus, is known as well.