Elapidae, Boie, 1827

Ivanov, Martin, 2002, The oldest known Miocene snake fauna from Central Europe: Merkur-North locality, Czech Republic, Acta Palaeontologica Polonica 47 (3), pp. 513-534 : 529-530

Elapidae gen. et sp. indet.

C

Material.—Three trunk vertebrae ( SGDB 7408/MI−89–91), 6 trunk vertebrae ( SGDB Ah−604–609).

Trunk vertebrae ( Fig. 10A–E ).—In lateral view, the neural spine is very low and does not overhang either anteriorly nor posteriorly. The interzygapophyseal ridges are strongly developed and the lateral foramina usually occur in depressions (with exception of posterior trunk vertebrae). The paradiapophyses are clearly divided and the diapophysis is much more smaller than the parapophysis. The parapophyseal processes are short. The subcentral ridges are very short and arched dorsally and in posterior trunk vertebrae are longer and strongly developed. The hypapophysis is very short and its distal tip is situated close to the anterior margin of the condyle. The condyle has a short neck. In dorsal view, the cranial margin of the zygosphenal lip has distinct lateral lobesandtheprominentmedianlobeiswide.Theprezygapophyseal articular surfaces are obovate and the prezygapophyseal processes are short and pointed. The epizygapophyseal spines are missing. In ventral view, the subcentral ridges of the anterior trunk vertebrae are indistinct and the subcentral grooves are underdeveloped. In posterior trunk vertebrae, both the subcentral ridges and subcentral grooves are strongly developed. The subcentral foramina are shifted anteriorly and occur at the base of the wide hypapophysis. The hypapophysis distinctly deepens toward the condyle and the anterior keel is not triangularly expanded. The postzygapophyseal articular surfaces are obovate. In cranial view, the neural arch is slightly regularly vaulted, the neural canal is approximately circular with lateral sinuses, and the zygosphenal lip is convex. Distinct foramina occur at the base of the prezygapophyseal processes. The large paracotylar foramina occur in depressions on either side of the circular cotylar rim. In posterior trunk vertebrae the depressions for paracotylar foramina become deeper. Measurementsareasfollows(n=6):cl:or= 2.21–3.01mm;naw:or= 1.57–2.21 mm; cl/naw: or = 1.34–1.59, mean l.47±0.09.

Comments.—The vertebrae are very small. The assignment to Elapidae gen. et sp. indet. (morphotype Elapidae A sensu Ivanov 1997a: 134–135, fig. 62) is based on the presence of hypapophyses in trunk vertebrae, very low neural spines, vaulted neural arches, and anteriorly directed parapophyseal processes. Therefore, the vertebrae probably belong to small cobra taxa. Several small elapids are reported from the German and French Early and Middle Miocene localities: Micrurus gallicus Rage and Holman, 1984 , “? Micrurus gallicus Rage and Holman, 1984 ”, Elapidae A(Rage and Holman 1984; Szyndlar and Schleich 1993; Ivanov 2000a). Micrurus sp. is reported from the Middle Miocene of Nebraska and the Late Miocene of Florida ( Holman 1977b, 2000). Representatives of the recent species M. fulvius are known from many Pleistocene localities in Florida and Texas ( Holman 1981b, 1995, 2000). Elapidae gen. et sp. indet. (very similar to the morphotype Elapidae A, reported from the French Early/ Middle Miocene, MN 4/5 locality at Vieux−Collonges, Ivanov 2000a) resembles extinct species M. gallicus in having elongated vertebral centra, the shape of the zygosphene, and the relatively deep caudal notch. The hypapophysis is directed caudally but in M. gallicus the hypapophysis is shorter. Elapidae gen. et sp. indet. differs from M. gallicus especially by its very low and indistinct neural spine and shorter prezygapophyseal processes (see also Ivanov 2000a). The vertebrae of Elapidae gen. et sp. indet. are most similar to the vertebrae of Elapidae indet. from the German Early Miocene (MN 4) locality at Petersbuch 2 compared to the genera Micrurus and Maticora ( Szyndlar and Schleich 1993; Szyndlar unpubl. data). Therefore, we can agree with assumption of Szyndlar and Schleich (1993) that the vertebrae from Petersbuch 2 (and now also from Merkur−North) belong to small “euproteroglyphous” elapids—i.e., subfamilies Calliopheinae, Maticorinae or Elapinae . Amore precise evaluation of taxonomic status of Elapidaegen.etsp.indet.cannotpresentlybemadebecauseof the lack of recent comparative material. Elapidae gen. et sp. indet. from Merkur−North (MN 3a) represents the oldest known member of this family.

Figures

Fig. 10. A–E. Elapidae gen. et sp. indet. from the Early Miocene (MN 3a) of Merkur−North; trunk vertebra (SGDB 7408/MI−89) in lateral (A), dorsal (B), ventral (C), cranial (D), and caudal (E) views. Scale bar 2 mm.