Batrachichnus salamandroides Geinitz, 1861

Moreau, Jean-David & Gand, Georges, 2022, New data on the Permian ecosystem of the Rodez Basin: ichnofauna (traces of protostomians, tetrapods and fishes), jellyfishes and plants from Banassac-Canilhac (Lozère, southern France), Geodiversitas 44 (31), pp. 975-987 : 980

Batrachichnus salamandroides Geinitz, 1861 ( Fig. 5 )

Material examined. — Six tracks; four tracks preserved as concave epireliefs and convex hyporeliefs on slabs M486_ 2022.1.6 A and M486_ 2022.1.6 B, respectively ; two tracks preserved as concave epireliefs on slab M486_ 2022.1.7.

DESCRIPTION

The tracks are small, plantigrade to semi-plantigrade. Pes imprints are pentadactyl and longer (PL = 1.5-4.0 mm) than wide (PW = 1.3-3.8 mm; Fig. 5 A-E) to as long as wide. The ratio PL/PW varies from 1.0-1.2. Digit imprints are straight and end in an enlarged, rounded tip ( Fig. 5 C-E). The divarication angle of digits I-V is up 85°. Pes tracks show a large rounded and well-marked sole ( Fig. 5 C-E). Manus imprints are tetradactyl, smaller than pes tracks and as long (ML= 1.3-2.3 mm) as wide (MW= 1.3-2.8 mm) to slightly wider than long. The ML/MW ratio varies from 0.8 to1.0. Digit imprints are straight and end in an enlarged, rounded tip. The divarication angle of digits I-IV varies from 46° to 73°. Manus tracks show a short and large sole with a concave proximal margin ( Fig. 5A, B ).

REMARKS

The presence of the tetradactyl manus imprints as well as the rounded digit apex are characteristic of the ichnogenera Batrachichnus Woodworth, 1900 and Limnopus Marsh, 1894 . The two ichnogenera are distinguished based on their sizes. Manus imprints of Batrachichnus are less than 40 mm in length whereas tracks of Limnopus are larger (up to 200 mm in length; Voigt & Lucas 2018). Regionally, the ichnospecies Batrachichnus salamandroides was reported from the Saint-Affrique Basin ( Gand 1987, 1993b; Gand & Haubold 1984), the Lodève Basin ( Ellenberger 1983b; Gand & Durand 2006) and the Rodez Basin ( Gand 1987). The ichnospecies Batrachichnus salamandroides was also reported from southeastern France, in the Estérel Basin (Provence; Gand & Durand 2006). This ichnospecies is for the first time reported from Le Bousquet.

Figures

FIG. 5. — Batrachichnus salamandroides Geinitz, 1861: A, B, slab bearing a trackway with pes (p.) and manus (m.) track (a pes/manus set in visible in the bottom part of the picture), and co-occurring with a conifer leafy axis (c) (cf. Walchia, in the top of the picture), photograph (A) and interpretative sketch (B); C-E, pes track, photograph (C), digital elevation model in false colours (D) and interpretative sketch (E). Convex hyporeliefs, M486_2022.1.6B. Scale bars: 1 cm.