Coluber hungaricus ( Bolkay, 1913 )

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 : 426-428

Coluber hungaricus ( Bolkay, 1913)

Zamenis hungaricus Bolkay, 1913: 223 , 224, pl. XXII, fig. 3. — Kuhn 1939: 28.

Zamenis cf. Dahli – Szunyoghy 1932: 10 + 49.

Coluber cf. najadum – Młynarski 1961: 23.

Coluber hungaricus – Kuhn 1963: 20. — Rage 1984a: 44. — Szyndlar 1991a: 115; 2005: 35, 36, fig. 3. — Venczel 1994: 2-7, figs 1, 2; 2001: 85, fig. 5f-i.

Coluber hungaricus [part] – Venczel 1998: 2-6, figs 1-3.

MATERIAL. — 1 cervical vertebra ( BSPG 1997 XIII 541); 9 trunk vertebrae ( BSPG 1997 XIII 542-550).

LOCALITY. — Griesbeckerzell 1a.

DESCRIPTION

Cervical vertebra ( Fig. 8A )

The only preserved cervical vertebra comes from the posterior part of the cervical region as indicated by the short postero-ventrally directed hypapophysis in lateral view. The diapophysis is as large as the parapophysis and the parapophyseal process is short. The dorsally arched subcentral ridges are blunt but well developed. The neural spine is broken off at the base. Lateral foramina are distinct.

In dorsal view, the vertebra is short and the cranial margin of the zygosphene has a distinct median lobe as well as lateral lobes. Prezygapophyseal articular facets are broadly oval; the left prezygapophyseal process is slender and possesses a pointed distal tip. The process is directed antero-laterally.

In ventral view, the subcentral foramina are small but distinct. The only preserved left postzygapophyseal articular facet is subsquarish.

In cranial view, the neural arch is arched and the neural canal is subsquare and has short and wide lateral sinuses. The zygosphenal lip is dorsally arched. Paracotylar foramina occur in deep depressions on both sides of the dorso-ventrally depressed cotyle.

Trunk vertebrae ( Fig. 8B, C )

Vertebrae are typical because of their small dimensions. In lateral view, the neural spine of the posterior trunk vertebra (BSPG 1997 XIII 549) indicates posterior inclination of the caudal margin; the cranial margin was inclined anteriorly. The interzygapophyseal ridges are short and only weakly developed. Lateral foramina are small but distinct, and situated in depressions just beneath the interzygapophyseal ridges. Subcentral ridges are well developed and may run to the vicinity of the condyle. In anterior trunk vertebrae the subcentral ridges are blunt while they are more distinct in the only preserved posterior trunk vertebra. Synapophyses are partially damaged, but it is obvious that the parapophyses were as large as the diapophyses.

In dorsal view, the cranial margin of the zygosphene displays a wide median and well developed lateral lobes. The anterior base of the neural spine arises from the middle of the zygosphene.Prezygapophyseal articular facets are oval and somewhat enlarged; the only preserved right prezygapophyseal process is short and acute,reaching about half of the prezygapophyseal facet length. The incision in the caudal margin of the neural arch is relatively deep.

In ventral view, the triangular centrum is elongated and the haemal keel is well developed, sharp

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in the middle, and becoming more spatula-shaped towards the tips. The subcentral grooves are shallow and the subcentral ridges are strong and rounded with the only exception of one posterior trunk vertebra in which the subcentral ridges are more distinct, especially in their anterior part. Parapophyseal processes are very short. Postzygapophyseal articular facets are subsquare or subquadrate in shape. Subcentral foramina are very small and usually indistinct.

In cranial view, the neural arch is moderately vaulted and the neural canal is rounded or quadrate-shaped with small and relatively narrow lateral sinuses. The zygosphenal lip is either dorsally arched or almost straight. The large paracotylar foramina are situated in deep depressions on both sides of the dorso-ventrally slightly depressed cotyle.

In caudal view, the zygantral area is distinctly widened. The condyle is damaged in most vertebrae and dorso-ventrally slightly depressed. Measurements are as follows (n = 5): cl: or = 2.95-4.37 mm; naw: or = 2.27-3.01 mm; cl/naw: or = 1.14-1.45, mean 1.30 ± 0.11.

DISCUSSION

Coluber hungaricus belongs to an assemblage that has been labelled small colubrine snakes and it differs from the extant Coluber gemonensis (Laurenti, 1768) ( Hierophis gemonensis sensu Schätti & Utiger 2001 ) by the longer and distally pointed prezygapophyseal processes ( Venczel 1994). This snake from Griesbeckerzell 1a resembles Coluber hungaricus , which has been reported from the several Hungarian localities (e.g., Rudabánya [early Pannonian]; Polgárdi 2, 4, 5 [late Pontian]; and Osztramos 1 [early Dacian]; Venczel 1994, 1998; Szyndlar 2005), especially with regard to the following features: 1) shape and length of prezygapophyseal processes if compared with the material from Polgárdi 4 ( Venczel 1994); however, middle-trunk vertebrae of Coluber hungaricus from Rudabánya possess somewhat shorter prezygapophyseal processes ( Szyndlar 2005); 2) shape of the zygosphenal lip; 3) presence of blunt subcentral ridges and shallow subcentral grooves; and 4) length of the parapophyses and diapophyses.

Figures

FIG. 8.— Coluber hungaricus (Bolkay,1913) from the Middle Miocene (MN 6, base) of Griesbeckerzell 1a, in lateral (l), dorsal (d), ventral (v), cranial (cr) and caudal (ca) views: A, posterior cervical vertebra (BSPG 1997 XIII 541); B, middle trunk vertebra (BSPG 1997 XIII 547); C, posterior trunk vertebra (BSPG 1997 XIII 549). Abbreviations: see Figures 4, 6 & 7. Scale bars: 2 mm.