Anguidae

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 : 854

Anguidae ( Fig. 14U–Z )

Anguids have a subtriangular orbitonasal flange projection, which is wider but very slightly shorter than the slender and truncated posteroventral process ( Fig. 14V, Y ). There is no ornamentation in Anguis gr. An. fragilis ( Fig. 14U ), whereas very mild rugosities are visible dorsally in Pseudopus apodus at the base of the dorsal process ( Fig. 14X ). A distinct posterolateral projection is absent and the notch for the lacrimal foramen is wide and moderately ( Anguis gr. An. fragilis ; Fig. 14U–W ), or very, deep ( Pseudopus apodus ; Fig. 14X–Z ). The dorsal process is slender and moderately long, being as long as, or slightly longer than, the rest of the prefrontal in lateral view.The palpebral crest is low; in adults of Anguis gr. An. fragilis it is not clearly recognizable.

JUGAL

Jugals ( Fig. 16 ) are curved and paired bones, roughly L-shaped in lateral view, with an anterior and a posterodorsal process. The anterior process can have a medially developed shelf, the palatal process, whose posterior end can develop a triangular medial process of the jugal. Between the anterior and the posterodorsal processes, a quadratojugal process can develop in ventral direction. A row of small foramina pierces the lateral surface of the bone.

Figures

Figure 14. Prefrontals – A–B, Laudakia stellio (HUJ.OST-Z-5), right prefrontal in dorsal (A) and dorsolateral (B) views. C, Chamaeleo chamaeleon (MNHN 2002–24), right prefrontal in posterior view. D–E, Chamaeleo chamaeleon (NHMW 611), left prefrontal in dorsal (D) and medial (E) views. F–H, Lacerta bilineata (MDHC 381), left prefrontal in dorsal (F), lateral (G) and posterior (H) views. I–K, Ophisops elegans (MDHC 281), right prefrontal in dorsal (I), posterior (J) and lateral (K) views. L–N, Ti. lepidus (MDHC 216), left prefrontal in dorsal (L), posterior (M) and lateral (N) views. O–Q, Ab. kitaibelii (MDHC 239), right prefrontal in dorsal (O), posterior (P) and lateral (Q) views. R–T, Tr. aurata (MDHC 280), left prefrontal in dorsal (R), posterior (S) and lateral (T) views. U–W, Anguis gr. An. fragilis (MDHC 102), left prefrontal in dorsal (U), posterior (V) and lateral (W) views. X–Z, Pseudopus apodus (MDHC 214), left prefrontal in dorsal (X), posterior (Y) and lateral (Z) views. Abbreviations: adp, anterodorsal process; dp, dorsal process; n, notch of the lacrimal foramen; ofp, orbitonasal flange projection; onf, orbitonasal flange; pc, palpebral crest; pj, projection; pvp, posteroventral process; t, tubercle. Scale bars = 1 mm.

Figure 16. Jugals – A–B, Laudakia stellio (HUJ.OST-Z-424), left jugal in lateral (A) and medial (B) views. C–D, Chamaeleo chamaeleon (NHMW 611), left jugal in lateral (C) and medial (D) views. E–F, Ac. erythrurus (UAM.R.ACVII), left jugal in lateral (E) and medial (F) views (the dorsal margin of the anterior process is damaged). G–H, Ophisops elegans (MDHC 281), left jugal in lateral (G) and medial (H) views. I–J, Psammodromuss algirus (UAM.R.Ps9), right jugal in lateral (I) and medial (J) views. K–L, Ti. lepidus (MDHC 216), right jugal in lateral (K) and medial (L) views. M–N, Ab. kitaibelii (MDHC 239), right jugal in lateral (M) and medial (N) views. O–P, Chalcides chalcides (MDHC 398), left jugal in lateral (O) and medial (P) views. Q–R, Ophiomorus punctatissimus (MDHC 427), left jugal in lateral (Q) and medial (R) views. S–T, Anguis gr. An. fragilis (MDHC 102), right jugal in lateral (S) and medial (T) views. U–V, Pseudopus apodus (MDHC 215), left jugal in lateral (U) and medial (V) views. Abbreviations: ap, anterior process; asm, articulation surface with the maxilla; aspo, articulation surface with the postorbital; mp, medial process; pdp, posterodorsal process; pp, palatal process; qjp, quadratojugal process. Scale bars = 1 mm.