Naja cf. romani (Hoffstetter, 1939)

Vasilyan, Davit, Cernansky, Andrej, Szyndlar, Zbigniew & Moers, Thomas, 2022, Amphibian and reptilian fauna from the early Miocene of Echzell, Germany, Fossil Record 25 (1), pp. 99-145 : 99

Naja cf. romani

Fig. 18K-O

Material.

Four fangs HLMD-Ez 2157, 50 trunk vertebrae HLMD-Ez 2151-5156.

Description.

Fangs: Four isolated teeth are venomous fangs. They are tubular, with acute distal tips. The discharge orifice, located on the anterior surface of each fang, is elongate and gladiate-shaped. The discharge orifice extends, towards the proximal end, in the form of a visible suture. The latter condition is characteristic of elapid snakes, whereas in viperids the anterior surface of the fang is generally smooth. Relatively small dimensions of the fangs suggest that they either belonged to juvenile / subadult individuals or were replacement (non-functional) fangs.

Vertebrae: Most vertebrae come from the middle trunk portion of the column. In the largest (but partly damaged) vertebra (HLMD-Ez 2151, Fig. 18K-O ), centrum length measures 7.1 mm, centrum width - 5.7 mm, and centrum length / centrum width ratio equals 1.25. At least in large vertebrae, the centrum is triangular in ventral view, with a flat or slightly concave ventral surface. The subcentral ridges are well developed, especially behind the paradiapophyses. The hypapophysis, preserved partly in few vertebrae, is thick, strongly inclined posteriorly and shows a straight anteroventral margin. The neural arch is rather depressed. The neural spine, preserved partly in few vertebrae, is approximately twice longer than high. Its anterior margin is straight. The shape of the posterior margin is unknown. The paradiapophyses are well developed with short but distinct parapophyseal processes (the latter is preserved only in two vertebrae). The zygosphenal roof is almost straight or slightly convex in dorsal view. The prezygapophyseal and postzygapophyseal articular facets are relatively small and oval-shaped. The prezygapophyseal process (preserved only on the left side of one vertebra) is well developed, somewhat shorter than the articular facet and possesses also a moderately obtuse tip. The cotyle and condyle are suborbicular or slightly depressed. The subcentral, lateral, and paracotylar foramina are distinct (Fig. 18K-M ).

A few trunk vertebrae coming from the posterior trunk portion of the vertebral column are more elongated than those from the middle portion. One vertebra (HLMD-Ez 2154; centrum length 4.1 mm, centrum width is 3.0 mm, centrum length / centrum width ratio 1.4) is provided with a completely preserved hypapophysis. The hypapophysis is dagger-shaped and directed posteriorly.

Remarks.

Based on the overall vertebral morphology, cobras can be rather easily differentiated from other European fossil snakes. The vertebrae of cobras “mimic” the morphological pattern characteristic of large-sized “colubrines” but, unlike the latter, they are provided with hypapophyses throughout the trunk portion of the column. The vertebrae described above generally display the anatomical features characteristic (e.g., dagger-shaped and posteriorly directed hypapophysis) of the extinct species Naja romani ( Szyndlar 2005). Considering the fragmentary state of preservation of the fossils, we prefer to use the species name with the qualifier “cf.”.

Figures

Figure 18. Snakes from the Echzell. A-E. Bavarioboa cf. hermi (HLMD-Ez 2148), middle trunk vertebra; F-J. " Colubrinae " indet. (HLMD-Ez 2159), middle trunk vertebra; K, L. Naja cf. romani (HLMD-Ez 2151), middle trunk vertebra. All vertebrae in (A, F, K) lateral, (B, G, L) dorsal, (C, H, M) ventral, (D, I, N) anterior and (E, J, O) posterior views.