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 : 860

Chamaeleonidae ( Fig. 20C, D )

In Chamaeleo chamaeleon , the squamosal presents a dorsal parietal process and a quadrate process as in agamids, but they are more distinct, giving a Y-like shape to the bone. The anterior process is laminar and dorsoventrally expanded in lateral view; it contacts the postorbital anterodorsally and the jugal anteriorly. The quadrate process is rod-like and has a medial expansion by its ventral end ( Fig. 20D ); this is the shortest branch of the bone and contacts the paroccipital process of the otooccipital medially and the quadrate ventrally. The slender dorsal parietal process is the longest branch; it is slightly curved in the dorsal direction and has a rounded end contacting the posterior end of the parietal crest. The lateral surface of the bone is smooth, except for a few tubercles present on the dorsal margin of the anterior end of the dorsal parietal process ( Fig. 20C ). However, no tubercles are present on MNHN 1887-875.

Figures

Figure 20. Squamosals. A–B, Laudakia stellio (MDHC 245), left squamosal in lateral (A) and medial (B) views. C–D, Chamaeleo chamaeleon (NHMW 611), right squamosal in lateral (C) and medial (D) views. E–F, Po. muralis (MDHC 312), left squamosal in lateral (E) and medial (F) views. G–H, Lacerta viridis (MRAC 91-077-R-76), right squamosal in lateral (G) and medial (H) views. I–J, Chalcides chalcides (MDHC 398), right squamosal in lateral (I) and medial (J) views. K–L, Anguis gr. An. fragilis (MDHC 102), left squamosal in lateral (K) and medial (L) views. M–N, Pseudopus apodus (MDHC 215), left squamosal in lateral (M) and medial (N) views. Abbreviations: ap, anterior process; asjp, articulation surface with jugal and postorbital; dpp, dorsal parietal process; pp, posterior process; qp, quadrate process; r, ridge. Scale bars = 1 mm.