Vipera sp.

Ivanov, Martin & Böhme, Madelaine, 2011, Snakes from Griesbeckerzell (Langhian, Early Badenian), North Alpine Foreland Basin (Germany), with comments on the evolution of snake faunas in Central Europe during the Miocene Climatic Optimum, Geodiversitas 33 (3), pp. 411-449 : 439

Vipera sp.

(“European vipers” group; “ Vipera aspis complex”)

MATERIAL. — 1 precaudal vertebra ( BSPG 1997 XIII 659).

LOCALITY. — Griesbeckerzell 1a.

DESCRIPTION

Precaudal vertebra

The only preserved vertebra is very fragmentary. The neural spine was probably low, although only the base is preserved. The interzygapophyseal ridges are narrow and short. Synapophyses are heavily damaged, but the base of the parapophysis indicates that the parapophyseal processes were directed antero-ventrally. The subcentral ridges are distinct, long, and straight. The preserved base of the hypapophysis shows that its distal tip was directed postero-ventrally. Lateral foramina are small and indistinct.

In dorsal view, the vertebra is relatively short. The preserved left prezygapophysis possesses a prezygapophyseal articular facet that is roughly oval in shape. The epizygapophyseal ridges are underdeveloped.

In ventral view, the subcentral ridges are blunt and the subcentral grooves are well developed only in the anterior half of the vertebral length. Subcentral foramina are tiny and indistinct.

In cranial view, the neural arch is depressed and the neural canal is rounded with wide lateral sinuses. The cotylar rim was probably slightly depressed dorso-ventrally. Its diameter was originally somewhat larger than the diameter of the neural canal. The preserved left prezygapophysis is tilted dorsally. Paracotylar foramina are developed in deep depressions on both sides of the cotyle.

DISCUSSION

The vertebra is typical of viperids as shown by the dorso-ventrally depressed neural arch, tilted up prezygapophyses, and the presence of hypapophysis in precaudal vertebrae. A relatively high cl/naw (cl = 3.88 mm; naw = 2.80 mm; cl/naw = 1.39) and the postero-ventrally rather than posteriorly directed hypapophysis indicate assignation of the fossil vertebra to the “European vipers” group. Postero-ventral direction of hypapophysis in precaudal vertebrae is typical for “ Vipera aspis complex” (e.g., Szyndlar 1984; 1991b), but a more precise affiliation is impossible because of the preservation of the vertebra.