Scincidae

Scincidae View in CoL ( Fig. 19Q View Figure 19 –AD)

Scincids usually also have separate postfrontal and postorbital, but Evans (2008) stated that the postorbital apo, articulation surface with the postorbital; asf, articulation surface with the frontal; asj, articulation surface with the jugal; asp, articulation surface with the parietal; asq, articulation surface with the squamosal; ex, osseous expansion; pp, posterior process; vp, ventral process. Scale bars = 1 mm.

may be reduced or lacking. The postorbital is present in Chalcides and Ophiomorus punctatissimus , but it appears to be absent in Ab. kitaibelii and it has not been possible to find it in the studied specimens of Tr. aurata . Nevertheless, in the latter case, this may be also due to a loss during preparation rather than to an actual absence of the bone in this species. The postfrontal is Y-shaped, with a laminar body, two pointed (rounded in Ophiomorus punctatissimus ; Fig. 19W–X View Figure 19 ) processes on the anterior corners and a concave anterior margin ( Fig. 19Q–Z View Figure 19 ). In dorsal view, the body is slender and triangular in Ab. kitaibelii ( Fig. 19Q, R View Figure 19 ), slender and subrectangular in Chalcides chalcides , Chalcides striatus and Ophiomorus punctatissimus ( Fig. 19S, T, W, X View Figure 19 ), wider and laterally expanded in the posterior-half in Chalcides ocellatus ( Fig. 19U, V View Figure 19 ), and wider and provided with a moderately developed and pointed posterior projection on the posterolateral corner in Tr. aurata ( Fig. 19Y, Z View Figure 19 ). A similar projection is also present in Ophiomorus punctatissimus ( Fig. 19W, X View Figure 19 ). Both the dorsal and the ventral surfaces are smooth, but a variable number of foramina can pierce the laminar body of the bone. In Chalcides chalcides , the anterolateral process is moderately developed, similar in size and length to the anteromedial one and slightly curved posteriorly at its distal end ( Fig. 19S, T View Figure 19 ). The anteromedial process is also moderately developed, but it is straight. Chalcides ocellatus and Tr. aurata , on the other hand, have a moderately large and long anteromedial process, which is longer than the anterolateral one ( Fig. 19U, V, Y, Z View Figure 19 ). Moreover, in the latter species, both processes are straight. Ablepharus kitaibelii , Chalcides striatus and Ophiomorus punctatissimus also have a longer anteromedial process, but it is more slender ( Fig. 19Q, R, W, X View Figure 19 ). The medial margin of the bone is distinctly dorsoventrally enlarged, forming a concave articulation surface for the contact with both the frontal and parietal, whereas the lateral one has only a narrow articular surface housing the postorbital (or the posterodorsal process of the jugal, when the postorbital is absent). In Ab. kitaibelii , the concavity for the articulation with the frontal and parietal is very poorly developed and, therefore, the medial margin is not much expanded. The posterior end of the bone can be irregular because of a lower degree of ossification. The postorbital ( Fig. 19 View Figure 19 AA–AD) is an L-shaped and slender rod, with a short anterolateral process and a long posterior process. The distal end of both processes is pointed. In Chalcides ocellatus , this bone is more robust than in the other species ( Fig. 19 View Figure 19 AC–AD). The articulation surfaces with the postfrontal and the squamosal are recognizable in Chalcides ocellatus and Ophiomorus punctatissimus , on the medial side of the ventral surface and on the lateral side of the dorsal surface, respectively.