Lacertidae

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 : 873

Lacertidae ( Fig. 29K–P )

In lacertids, the ectopterygoid is L-shaped and is composed of three processes. The anterolateral process is laminar and pointed; its ventral surface is covered by the articulation surface with the maxilla. The posterolateral process is short or very short and pointed. The posteromedial process has a V-shaped concavity at its end in which the pterygoid flange of the pterygoid inserts. The concavity is defined by three lappets, among which the anteromedial one is the longest one. The ventral lappet is more developed than the dorsal one. Usually, the longest process is the posteromedial one, even though this feature can be variable among different individuals ( Barahona, 1996). However, this is not true for Ac. erythrurus , Al. marchi , Ophisops elegans and Po. muralis , in which this process is usually as long as the anterolateral one ( Fig. 29K, L ), and for Z. vivipara , in which they can be similar in length or the longest process may even be the anterolateral one ( Fig. 29O, P ). The dorsal surface of the bone is smooth.

Figures

Figure 29. Ectopterygoids. A–E, Laudakia stellio (MDHC 245), left ectopterygoid in anterior (A), dorsal (B), ventral (C), medial (D) and lateral (E) views. F–J, Chamaeleo chamaeleon (MNHN 2002–24), right ectopterygoid in anterior (F), dorsal (G), ventral (H), medial (I) and lateral (J) views. K–L, Ac. erythrurus (UAM.R.ACVII), right ectopterygoid in ventral (K) and dorsal (L) views. M–N, Lacerta agilis (MDHC 176), left ectopterygoid in ventral (M) and dorsal (N) views. O–P, Z. vivipara (UAM.R.Lv24), right ectopterygoid in ventral (O) and dorsal (P) views. Q–R, Ab. kitaibelii (MDHC 239), right ectopterygoid in ventral (Q) and dorsal (R) views. S–T, Chalcides ocellatus (MDHC 250), right ectopterygoid in ventral (S) and dorsal (T) views. U–V, Ophiomorus punctatissimus (MDHC 427), right ectopterygoid in ventral (U) and dorsal (V) views. W–X, Tr. aurata (MDHC 280), right ectopterygoid in ventral (W) and dorsal (X) views. Y–Z, Anguis gr.An. fragilis (MDHC 102), right ectopterygoid in ventral (Y) and dorsal (Z) views. AA–AB, Pseudopus apodus (MDHC 215), left ectopterygoid in ventral (AA) and dorsal (AB) views. Abbreviations: al, anteromedial lappet of the posteromedial process; alp, anterolateral process; asm, articulation surface with the maxilla; asp, articulation surface with the pterygoid flange; dl, dorsal lappet of the posteromedial process; plp, posterolateral process; pmp, posteromedial process; vl, ventral lappet of the posteromedial process; vp, ventral process. Scale bars = 1 mm.