Scincidae

Scincidae View in CoL ( Fig. 43I–P View Figure 43 )

The mandibular symphysis is narrow and almost horizontal in the dentaries of European scincids too. The Meckelian fossa is wide in its posterior-half and very narrow in the anterior one. Moreover, the anterior-half of the fossa opens in the ventral direction, because a ventral expansion of the subdental shelf covers it medially. The remaining portion of the shelf is narrow, like in lacertids. Caputo (2004) stated that some specimens of Chalcides ocellatus can have a partly closed fossa, probably because of a strong ventral development of the subdental shelf. This happens also in Tr. aurata (e.g. MDHC 280; Fig. 43O View Figure 43 ). Ablepharus kitaibelii has an almost entirely closed Meckelian fossa, which opens only at the anterior and posterior ends of the tooth row with narrow notches ( Fig. 43I View Figure 43 ). European scincids display well-distinct subdental ridge and sulcus dentalis, like in lacertids. As in other tooth-bearing bones of this family, teeth are morphologically similar to those of gekkotans [see above and Villa et al. (2018a)], except for a slightly posteriorly curved crown provided with a light striation on the lingual surface. Exceptions are Chalcides ocellatus , whose teeth are robust and provided with a blunt and enlarged crown ( Fig. 43K, L View Figure 43 ), and Ophiomorus punctatissimus , in which teeth are increasingly more robust towards the posterior end of the tooth row (but the last tooth position is smaller than the preceding ones; Fig. 43M, N View Figure 43 ). The morphology of the posterior processes is usually similar to the one presented by gekkotans (i.e. inferior process long and pointed, superior process smaller and composed of two pointed projections; Villa et al., 2018a), but the notch separating the projections of the superior one is shallow and roughly U-shaped. Moreover, the largest projection of the superior process is usually the dorsal one, whereas the ventral one is small. In Ab. kitaibelii , the latter is not recognizable and a rounded expansion can be present on the dorsal margin of the inferior posterior process ( Fig. 43I, J View Figure 43 ). Ophiomorus punctatissimus displays three posterior processes at its posterior end, because a central posterior process is located between the dorsal and the ventral ones ( Fig. 43M, N View Figure 43 ). The superior posterior process of Ophiomorus punctatissimus differs from that of other European scincids, because it is distinctly directed posterodorsally and not composed by separated projections ( Fig. 43M, N View Figure 43 ). In the same species, the three processes can be either roughly similar in size (e.g. in MDHC 427) or the central one can be smaller than the others (e.g. in MCZ 38517). In medial view, the ventral margin of the dentary is straight. Measurements, number of tooth positions and mental foramina, and the position of the posterior end of the intramandibular septum are given in the Supporting Information 4.