Natrix, Laurenti, 1768

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 : 430

Natrix cf. N. longivertebrata Szyndlar, 1984

MATERIAL EXAMINED. — 1 trunk vertebra (Béon 2004 LT 69).

COMMENTS

A single, incomplete specimen displays the characteristic traits of N. longivertebrata : vertebra elongate; centrum narrow, elongate, and limited by strong subcentral ridges; hypapophysis prolonged anteriorly by a salient ridge; prezygapophyseal processes stout and dorsoventrally flattened; neural arch depressed; neural spine very low, overhanging anteriorly and whose dorsal edge slopes posteriorly; parapophyseal processes strong and clearly directed anteriorly. Despite the fact that all these characters are observable, this single, damaged specimen cannot be assigned to N. longivertebrata without reservation. Vertebrae of N. longivertebrata were illustrated by Szyndlar (1984: fig. 29; 1991b: fig. 3) and Bachmayer & Szyndlar (1985: fig. 2).

N. longivertebrata is closely related to the living N. natrix ( Szyndlar 1991b; Ivanov 1999). It is known from the Pliocene (MN 14 to MN 16) of Hungary, Poland, and Moldova ( Szyndlar 1991c; Venczel 2001). Natrix aff. N. longivertebrata was reported from the middle Miocene of Sansan (MN 6) and La Grive L7, and perhaps La Grive L3 (MN 7+8) ( Rage & Szyndlar 1986; Augé & Rage 2000). The species is perhaps present (N. cf. N. longivertebrata ) in the late Miocene of Austria, Hungary, and Ukraine ( Szyndlar & Zerova 1992; Venczel 1998). Consequently, if the vertebra from Béon 1 really belongs to N. longivertebrata , then it represents the earliest occurrence of the species.