Eubrontes veillonensis ” Lapparent & Montenat, 1967

Moreau, Jean-David, Vullo, Romain, Bichr, Elsie, Thomas, Jérôme, Gand, Georges, Gagnaison, Cyril, Barrier, Pascal & Néraudeau, Didier, 2024, Crocodylomorph and dinosaur tracks from the lowermost Jurassic of Le Veillon (western France): ichnotaxonomic revision of the type material (Lapparent collection), Geodiversitas 46 (8), pp. 343-366 : 357

“ Eubrontes veillonensis ” Lapparent & Montenat, 1967

( Fig. 9 A-C)

Eubrontes veillonensis Lapparent & Montenat, 1967: 23-27 , pl. XI.2- 4, fig. 12.

STATUS. — Subjective junior synonym of Eubrontes giganteus Hitchcock, 1845 .

EXAMINED MATERIAL. — Holotype: ULB-04D21_A (plaster cast).

DESCRIPTION

The track is tridactyl, longer than wide (L/W = 1.3), 34 cm long and 26.5 cm wide ( Fig. 9 A-C; Table 2 ). The divarication angle between digits II and IV is quite large (II-IV = 40°) and D is short (L/D = 3.5). Impressions of digits are particularly wide with well-distinguished and marked pads. The digito-metatarsal pad of digit IV is more proximal than that of digit II. Tracks display elongated and pointed claw marks.

REMARKS

Based on an in situ trackway composed of twelve footprints, Lapparent & Montenat (1967) erected (without diagnosis) the ichnospecies “ Eubrontes veillonensis ”. ULB-04D21_A ( Fig. 9 A-C) is the plaster cast of one of the best-preserved footprints of this trackway. A recent survey in 2022 on the tidal flat from Le Veillon could not relocate the specimen, which was most probably destroyed. E. giganteus Hitchcock, 1845 was introduced based on tridactyl tracks from the Early Jurassic rocks of the Dinosaur Footprint Reservation in Holyoke, Massachusetts ( Olsen et al. 1998). In Fig. 4 , ULB-04D21_A is compared with Early Jurassic Eubrontes giganteus specimens from France and from the United States. This analysis shows that the Eubrontes track from Le Veillon fully falls within the morphological range of this ichnospecies. E. giganteus and “ E. veillonensis ” show similar shape of footprints with massive impressions of digits II, III and IV bearing well-marked pads and long claw marks as well as the presence of a well-marked digito-metatarsal pad of digit IV more proximal than that of digit II. Based on these observations we consider “ E. veillonensis ” as a subjective junior synonym of E. giganteus .

Figures

FIG. 9. — Eubrontes giganteus Hitchcock, 1845: A-C, track ULB-04D21_A (plaster cast of the holotype of “E. veillonensis” that is here invalidated), photograph (A), DEM and false-colour depth map (B) and interpretative sketch (C). Scale bars: 10 cm.

FIG. 4. — Footprints from Le Veillon compared to tridactyl tracks from the Early Jurassic of the Causses Basin (based on data from Demathieu et al. 2002; Moreau et al. 2021) and the Early Jurassic of the eastern United States (based on data from Weems 1992, 2019; Gand et al. 2018): A, bivariate diagram L vs (L–D)/D; B, bivariate diagram L vs L/W. L in metres.