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 : 871

Chamaeleonidae ( Fig. 27W, X )

In Chamaeleo chamaeleon , the main feature of the pterygoid is the wing-like quadrate process, which is laminar and very dorsoventrally expanded, forming a posteriorly rounded flange. The medial surface of the flange presents a well-developed ridge in the middle, marking the deep basipterygoid fossa ( Fig. 27X ). Ventrally to this ridge, the quadrate process expands to form another large and laminar flange guiding the coronoid. This latter flange has a roughly subtriangular shape in medial view and a rounded ventral end. Moreover, the pterygoid of Chamaeleo chamaeleon loses the triradiate shape, since the pterygoid flange is reduced to a ridge located on the anterior margin of the ventral flange of the quadrate process ( Fig. 27W ). The ridge is more developed in its dorsal portion and the articulation surface with the ectopterygoid is recognizable on its anterolateral surface. The slender palatine process is straight and triangular in ventral view. The oblique suture with the palatine is present anterolaterally. There are neither pterygoid teeth nor fossa columellae. Maximum length goes from 7 mm to 12.9 mm.

Figures

Figure 27. Pterygoids. A–B, Laudakia stellio (HUJ.OST-Z-423), right pterygoid in dorsal (A) and ventral (B) views. C–D, Al. fitzingeri (MDHC 351), left pterygoid in dorsal (C) and ventral (D) views. E–F, Ti. lepidus (MDHC 216), left pterygoid in dorsal (E) and ventral (F) views. G–H, Ab. kitaibelii (MDHC 239), left pterygoid in dorsal (G) and ventral (H) views. I–J, Chalcides chalcides (MDHC 94), left pterygoid in dorsal (I) and ventral (J) views (the tip of the pterygoid flange is broken). K–L, Chalcides ocellatus (MDHC 250), right pterygoid in dorsal (K) and ventral (L) views. M–N, Ophiomorus punctatissimus (MDHC 427), right pterygoid in dorsal (M) and ventral (N) views. O–P, Tr. aurata (MDHC 280), left pterygoid in dorsal (O) and ventral (P) views. Q–R, Anguis gr. An. fragilis (MDHC 102), right pterygoid in dorsal (Q) and ventral (R) views. S–T, Pseudopus apodus (MDHC 215), left pterygoid in dorsal (S) and ventral (T) views (the anterior end of the palatine process is broken). U–V, Laudakia stellio (HUJ.OST-Z-423), right pterygoid in lateral (U) and medial (V) views. W–X, Chamaeleo chamaeleon (NHMW 611), right pterygoid in lateral (W) and medial (X) views. Abbreviations: bf, basipterygoid fossa; bp, basisphenoid process; fc, fossa columellae; isp, insertion surface of the pterygoideus muscle; pf, pterygoid flange; pp, palatine process; pre, pterygoid recess; pri, pterygoid ridge; qp, quadrate process; rpm, ridge for the insertion of the pterigomandibular muscle; rsp, ridge for the insertion of the superficial pseudotemporal muscle; vf, ventral flange. Scale bars = 1 mm.