Vipera 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 : 433-434

Vipera sp.

MATERIAL EXAMINED. — 13 trunk vertebrae (Béon 2004 LT 82; Béon 93 E3 SN 5).

COMMENTS

This viper is comparatively small (centrum length of largest vertebra: 4.8 mm). All neural spines are broken away and only one posterior trunk vertebra preserves a hypapophysis. The vertebrae are not elongate, which rules out a referral to the “ berus complex”. The overall proportions of the specimens from Béon 1 are consistent with those in species of the “ Vipera aspis complex”. The hypapophysis of the posterior trunk vertebra is slightly curved posteriorly as in the living V. aspis (Linnaeus, 1758) and V. latastei Boscá, 1878 . No further comparison is possible.

The aspis complex is an informal subdivision of the genus Vipera defined by Szyndlar & Schleich (1993). Aside from living forms, three extinct species were referred to this complex. V. antiqua Szyndlar, 1987 is known from the late early Miocene (MN 4) of the Czech Republic and Germany ( Szyndlar 1987; Szyndlar & Schleich 1993). The earliest known viper, recovered from the earliest Miocene (MN 1) of Weisenau, Germany, perhaps belongs to this species ( Vipera cf. V. antiqua ; Szyndlar & Böhme 1993: 431). Despite the poor preservation of the fossils from Béon 1 it may be stated that they do not belong to V. antiqua . The hypapophysis of the posterior trunk vertebrae from Béon 1 is slightly curved whereas it is straight in V. antiqua . V. meotica Zerova, 1992 (in Szyndlar & Zerova 1992) is known from the late Miocene (MN 12 and perhaps MN 13) of Ukraine ( Zerova 1992; Szyndlar & Rage 2002). It differs from the viper of Béon 1 in having narrower and higher vertebrae, and perhaps shorter centra. V. natiensis Bailon, Garcia-Porta & Quintana-Cardona, 2002 , from the Pliocene of the Balearic Islands ( Bailon et al. 2002), has vertebrae more depressed than those of the small viperid from Béon 1 and the anterior border of their zygosphene is slightly concave whereas it forms a median lobe at Béon 1.