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 : 438

Vipera sp. (“ Oriental vipers” group)

MATERIAL EXAMINED. — 10 precaudal vertebrae ( BSPG 1997 XIII 649-658).

LOCALITY. — Griesbeckerzell 1a.

DESCRIPTION

Precaudal vertebrae ( Fig. 14B )

The neural spine is broken off at its base. In lateral view, the interzygapophyseal ridges are short; the lateral foramina are situated below the cranial part of the these ridges in depressions. Synapophyses are divided into dia- and parapophysis. The diapophysis is about as large as the parapophysis. If preserved, the narrow and long parapophyseal processes are directed antero-ventrally. The hypapophysis is massive and directed postero-ventrally. The distal tip of the hypapophysis is broken off.

In dorsal view, the vertebrae are relatively short. Prezygapophyseal articular facets are roughly oval and the prezygapophyseal processes are short and blunt. However, in one specimen, the distal tip of the left prezygapophyseal process ( BSPG 1997 XIII 656) is pointed. The cranial margin of the zygosphenal lip is characterized by a small median lobe ; the lateral lobes are prominent. The neural spine arises from the mid part of the zygosphene.

In ventral view, small (and sometimes indistinct) subcotylar tubercles are visible at the base of the cotylar rim. Subcentral ridges are blunt; they are visible only in the anterior half of the vertebral length in a similar way as the shallow and wide subcentral grooves. Subcentral foramina are small and situated at the base of the wide hypapophysis. Diapophyses are directed postero-laterally. Postzygapophyseal articular facets are subtriangular and slightly expanded laterally.

In cranial view, the prezygapophyses are tilted dorsally. The neural arch is usually depressed, but weakly vaulted in the best preserved vertebra. The neural canal is rounded with large and wide lateral sinuses. The cotyle is only slightly larger than the diameter of the neural canal. The cranial margin of the zygosphenal lip is slightly dorsally vaulted. The distal tip of the parapophyses is narrow, but they are blunt and directed ventrally or ventrolaterally, rather than medially. Distinct paracotylar foramina are situated in depressions on both sides of the rounded cotyle.

DISCUSSION

The vertebrae are relatively short, with a low cl/naw, but only two of the specimens have been measured: BSPG 1997 XIII 655: cl = 7.51 mm; naw = 7.38mm; cl/naw = 1.02; BSPG 1997 XIII 656: cl = 4.91 mm; naw = 4.29 mm; cl/naw = 1.14). The massive structure of the vertebrae and the strong hypapophysis represent a typical complement of features for the “ Oriental vipers” group. The cranial margin of the zygosphene, with the distinct lateral lobes and a small median lobe is similar to the zygosphene of the extant Vipera lebetina Linnaeus, 1758 ( Macrovipera lebetina sensu Hermann et al. 1992 ) reported by Szyndlar & Rage (1999: 10, fig. 1). However, a precise distinction between V.lebetina and V.xantina (Gray, 1849) ( Montivipera xanthina sensu Nilson et al. 1999 ) based exclusively on vertebral morphology is problematic ( Szyndlar & Rage 1999).

Figures

FIG. 14.— A, Vipera sp.(“Oriental vipers” group) or Daboia sp. from the Middle Miocene (late MN 5) of Griesbeckerzell 1b; trunk vertebra (BSPG 1997 XIII 646) in lateral (l), dorsal (d), ventral (v), cranial (cr), and caudal (ca) views; B, Vipera sp. (“Oriental vipers” group) from the Middle Miocene (MN 6, base) of the Griesbeckerzell 1a; trunk vertebra (BSPG 1997 XIII 656) in dorsal (d) ventral (v), and cranial (cr) views. Abbreviations: see Figures 4, 6, 7 & 13.