The genus Gopherus (Testudinidae): Pt. I. Osteology and relationships of extant species

Abstract

Adult skeletons of the extant species of the genus Gopherus were studied to determine the kind and level of similarities and differences between them and to form a comparative base for studies of fossil members of the genus. The skeleton and its variation in each of the species is described and/or figured and analyzed. The four extant species form two species groups, based on a number of osteological characters. One group includes G. polyphemus and G. flavomarginatus; the other G. berlandieri and G. agassizi. G. polyphemus and berlandieri represent the morphological extremes of each group. G. flavomarginatus and agassizi overlap in a number of characters, and may be close to the evolutionary base of both groups