Chamaeleonidae

Villa, Andrea & Delfino, Massimo, 2019, A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata), Zoological Journal of the Linnean Society 187 (3), pp. 828-928 : 882

Chamaeleonidae ( Fig. 37E–H )

In Chamaeleo chamaeleon , the sphenoid is larger than the basioccipital and has a subtrapezoidal body in ventral view. Well-developed cristae ventrolaterales are present and the basipterygoid processes are moderately long, moderately thick and roughly triangular. The processes enlarge distally and are tilted mediolaterally at an angle of about 45°. There are no supravenous processes and distinct grooves for the lateral head veins are not present. A well-developed and thick parasphenoid rostrum is present, whereas there are no trabeculae cranii ( Fig. 37E ). The crista sellaris is well developed and projects slightly anteriorly, creating a short dorsum sellae ( Fig. 37E ). The sella turcica is narrow and, therefore, the medial openings of the Vidian canals are close to each other. A very small foramen opens in the sella dorsomedially to the openings of the canals. The ventral surface of the bone is strongly concave and is bordered laterally by two well-developed ridges ( Fig. 37H ). The recessus vena jugularis is shallow ( Fig. 37G ).

Figures

Figure 37. Sphenoids. A–D, Laudakia stellio (MDHC 245), sphenoid in dorsal (A), anterior (B), left lateral (C) and ventral (D) views. E–H, Chamaeleo chamaeleon (MNHN 2002–24), sphenoid in dorsal (E), anterior (F), right lateral (G) and ventral (H) views. I–K, Al. nigropunctatus (MDHC 242), articulated sphenoid in dorsal (I), ventral (J) and anterior (K) views. L–M, Lacerta agilis (MDHC 231), sphenoid in dorsal (L) and anterior (M) views (the parasphenoid rostrum is broken). N–O, Ab. kitaibelii (MDHC 239), articulated sphenoid in dorsal (N) and anterior (O) views. P–Q, Chalcides ocellatus (MDHC 193), articulated sphenoid in dorsal (P) and anterior (Q) views. R–S, Anguis gr.An. fragilis (MDHC 49), sphenoid in dorsal (R) and anterior (S) views (the parasphenoid rostrum is broken). Abbreviations: af, abducens foramen; aov, anterior opening of the Vidian canal; ap, alar process; bp, basipterygoid process; cs, crista sellaris; ct, crista trabeculares; cvl, crista ventrolaterales; ds, dorsum sellae; icf, internal carotid foramen; pov, posterolateral opening of the Vidian canal; pr, parasphenoid rostrum; rvj, recessus vena jugularis; svp, supravenous process; tc, trabecula cranii. Scale bars = 1 mm.