Differences in shell morphology of Testudo graeca and Testudo hermanni, based on material from Bulgaria

Abstract

Two tortoises, Testudo graeca ibera Pallas, 1814 and Testudo hermanni boettgeri (Mojsisovics, 1889). inhabit Bulgaria. Certain features normally used for their identification, such as division of the supracaudal scute (divided in T. h. boettgeri; undivided in T. g. ibera), are not absolute. Seven whole shells of T. g. ibera and eleven of T. h. boettgeri were studied, and also a large series of shell fragments of both species. Based on analysis of 44 shell characters, T. h. boettgeri was distinguished by the following: maximal width of vertebral scute V clearly greater than maximal widths of other vertebral scutes; width of vertebral scutes II, III and IV smaller than width of pleural scutes I, II and III; medial length of pectoral scute equal or slightly greater than half the medial length of the hypoplastron; hypo-xiphiplastral suture distant from the corner of the inguinal notch; medial length of xiphiplastron less than maximal width (in females), or nearly half the maximal width (in males).