Vipera, Laurenti, 1768

Ivanov, Martin, Čerňanský, Andrej, Bonilla-Salomón, Isaac & Luján, Àngel Hernández, 2020, Early Miocene squamate assemblage from the Mokrá-Western Quarry (Czech Republic) and its palaeobiogeographical and palaeoenvironmental implications, Geodiversitas 42 (20), pp. 343-376 : 365

Vipera sp. (‘European vipers’ group)

( Fig. 13 A-H)

Vipera sp. 2 (‘European vipers’) – Ivanov & Musil 2004: 230.

Vipera sp. (‘European vipers’ group) – Ivanov et al. 2006: 229, table 2.

MATERIAL. — MWQ, early Miocene, Burdigalian, Orleanian, MN 4: 2/2003 Reptile Joint: three trunk vertebrae (Pal. 2022-2024).

DESCRIPTION

Trunk vertebrae

The vertebrae are rather fragmentary with the neural spines broken-off close to their bases, and loss of the paradiapophyses and hypapophysis. In lateral view, the interzygapophyseal ridge of the best-preserved vertebra (Pal. 2022) is short. The lateral foramina are situated just below the interzygapophyseal ridges. The subcentral ridges are clearly bent dorsally. In dorsal view, the cranial margin of the zygosphene has developed small lateral lobes and a wide medial lobe. The right prezygapophyseal articular facet is subtriangular to oval in outline. The prezygapophyseal process is rather short. The epizygapophyseal spines are moderately developed. In ventral view, the subcentral grooves are deep, possibly indicating a more posterior position of the vertebra within the precloacal region. The hypapophysis is strongly built, extending anteriorly into a short triangular anterior keel. In cranial view, the neural arch is depressed dorsoventrally, and the neural canal is rounded with prominent lateral sinuses. The cranial margin of the zygosphene is vaulted dorsally. Large paracotylar foramina occur on either side of the rounded cotyle. The vertebral dimensions of the largest vertebra (Pal. 2023) are as follows: cl = 3.75 mm; naw = 2.85 mm; cl/naw = 1.32.

REMARKS

The vertebrae are typically viperine with a dorsoventrally depressed neural arch and prezygapophyses tilted up dorsally. The vertebrae are assigned to the ‘European vipers’. Because of their small dimensions we conclude that the vertebrae could probably belong to the ‘ Vipera aspis ’ complex. A more precise identification is not possible because of poor preservation.

Figures

FIG. 13. — Vipera sp. (‘European vipers’ group) from the early Miocene (MN 4) of MWQ. Trunk vertebra Pal. 2022 (2/2003 Reptile Joint) in right lateral (A), dorsal (B), ventral (C) and cranial (D) views. Trunk vertebra Pal. 2023 (2/2003 Reptile Joint) in left lateral (E), dorsal (F), cranial (G) and caudal (H) views. Abbreviations: cd, condyle; ct, cotyle; hy, hypapophysis; nc, neural canal; ns, neural spine; pctf, paracotylar foramen; pof, postzygapophyseal articular facet; prf, prezygapophyseal articular facet; prp, prezygapophyseal process; scg, subcentral groove; scr, subcentral ridge; zy, zygosphene; zyg, zygantrum. Scale bars: 2 mm.