Triturus, Rafinesque, 1815

Rage, Jean-Claude & Bailon, Salvador, 2005, Amphibians and squamate reptiles from the late early Miocene (MN 4) of Béon 1 (Montréal-du-Gers, southwestern France), Geodiversitas 27 (3), pp. 413-441 : 416

Triturus aff. T. helveticus (Razoumowsky, 1789) ( Fig. 1B )

MATERIAL EXAMINED. — 21 trunk vertebrae (Béon 2004 LT 2-4).

COMMENTS

This species is represented by tiny vertebrae (average length of centrum: 1.47 ± 0.13 mm). The neural spine is long, high, thin, and sometimes slightly forked posteriorly. The median notch in the posterior border of the neural arch is moderately deep and wide. The neural arch is vaulted; the ratio neural arch height/vertebra height is 0.43 ± 0.03. The size of the ventral crests shows variation. The subcentral foramina are generally large.

The height of the neural spine and the clearly vaulted neural arch show that these vertebrae belong to the subgenus usually named “ Palaeotriton ” (sensu Bolkay 1928). The overall v e r t e b r a l m o r p h o l o g y i s s i m i l a r t o t h a t o f Triturus aff. T. helveticus reported from the middle Miocene (MN 6) of Sansan by Rage & Hossini (2000). This Triturus from Béon 1 appears to be the earliest representative of the T. helveticus group.

Figures

FIG. 1. — Caudata; A, cf. Chelotriton sp., trunk vertebra (Béon 2004 LT 1); B, Triturus aff. T. helveticus (Razoumowsky, 1789), trunk vertebra (Béon 2004 LT 2); C, Triturus cf. T. marmoratus (Latreille, 1800), trunk vertebra (Béon 2004 LT 5). Dorsal (d), left lateral (l), right lateral (r), and ventral (v) views. Scale bars: 2 mm.