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 : 885

Lacertidae ( Figs 30 , 31A–D , 38D )

In lacertids, the supraoccipital bears a cylindrical and stocky processus ascendens, which continues posteriorly on the dorsal surface of the bone with a low supraoccipital crest (sometimes sharper in adults of large species). The degree of ossification of the processus varies with growth and within species: in juveniles and small-sized species it is ossified only by its base, whereas in adults and larger species the ossification is more developed. Two lateral crests are present at the sides of the processus, running along the anterior margin of the bone and merging in the short marginal processes by the contact with the prootics. In most species, the anterolateral margins are convergent in dorsal view, giving a hexagonal shape to the bone ( Figs 30I , 31D , 38D ), but in Ac. erythrurus they are roughly parallel ( Fig. 30D ).

Figures

Figure 30. Braincases. A–E, Ac. erythrurus (UAM.R.ACVII), braincase in anterior (A), right lateral (B), posterior (C), dorsal (D) and ventral (E) views. F–J, Lacerta bilineata (MDHC 15), braincase in anterior (F), right lateral (G), posterior (H), dorsal (I) and ventral (J) views. The parasphenoid rostrum is broken in both specimens. Abbreviations: ap, alar process; asc, anterior semicircular canal; b, basioccipital; bp, basipterygoid process; ca, crista alaris; fma, foramen magnum; fo, fenestra ovalis; glhv, groove of the lateral head vein; hsc, horizontal semicircular canal; o, otooccipital; oc, occipital condyle; p, prootic; pap, paroccipital process; povc, posterior opening of the Vidian canal; rvj, recessus vena jugularis; sp, sphenoid; su, supraoccipital; tc, trabecula cranii. Scale bars = 1 mm.

Figure 31. Braincases (continued). A–E, Po. bocagei (UAM.R.PB48), braincase in anterior (A), left lateral (B), posterior (C), dorsal (D) and ventral (E) views. F–J, Ab. kitaibelii (MDHC 239), braincase in anterior (F), right lateral (G), posterior (H), dorsal (I) and ventral (J) views. Abbreviations: aovc, anterior opening of the Vidian canal; cc, cochlear cavity; cp, crista prootica; ip, incisura prootica; pp, posterior process of the prootic; psc, posterior semicircular canal; vf, vagus foramen. Scale bars = 1 mm.

Figure 38. Supraoccipitals. A, Laudakia stellio (MDHC 245), supraoccipital (broken) in dorsal view. B, Chamaeleo chamaeleon (MNHN 2002-24), supraoccipital in left lateral view. C, Chamaeleo chamaeleon (NHMW 611), supraoccipital in dorsal view. D, Po. muralis (MDHC 312), supraoccipital in dorsal view. E, Tr. aurata (MDHC 280), supraoccipital in dorsal view. Abbreviations: asc, anterior semicircular canal; lc, lateral crest; mc, median crest; mp, marginal process; pa, processus ascendens; psc, posterior semicircular canal. Scale bars = 1 mm.