Ophisaurus sp.

Rage, Jean-Claude & Bailon, Salvador, 2005, Amphibians and squamate reptiles from the late early Miocene (MN 4) of Béon 1 (Montréal-du-Gers, southwestern France), Geodiversitas 27 (3), pp. 413-441 : 425

Ophisaurus sp. ( Fig. 4C )

MATERIAL EXAMINED. — 1 fragmentary left dentary (Béon 2004 LT 49), and perhaps 1 pterygoid (Béon 2004 LT 50) and 20 vertebrae (Béon 2004 LT 51, 52).

COMMENTS

On the dentary, the subdental shelf and alveolar surface of the parapet form a single, inclined surface; as a result, the implantation of teeth is subpleurodont. The lamina horizontalis does not project medial to the bases of teeth. The teeth are conical; their apices are pointed, slightly recurved and not striated. Such teeth are reminiscent of those of Ophisaurus (sensu Klembara 1979, 1981; i.e. Dopasia Gray, 1853 included) of the European type. But a more precise identification is impossible.

One pterygoid and 20 vertebrae or so, that display the anguine morphology, are tentatively assigned to this taxon on the basis of size consistency. Moreover, the centrum is less widened anteriorly and the ventral surface more convex than in Pseudopus , and the subcentral ridges are slightly concave in ventral aspect.

Figures

FIG. 4. — A, B, Pseudopus laurillardi (Lartet, 1851); A, right dentary (Béon 2004 LT 39); B, posterior part of a braincase (Béon 2004 LT 38); C, Ophisaurus sp., left dentary (Béon 2004 LT 49). Dorsal (d), left lateral (l), medial (m), and right lateral (r) views. Abbreviations: dr, dorsal ridge; pms, posteromedial surface of paroccipital process; vb, ventral border of trigeminal notch. Scale bars: A, B, 5 mm; C, 2 mm.