Becklesius nopcsai, Folie & Codrea, 2005

Folie, Annelise & Codrea, Vlad, 2005, New lissamphibians and squamates from the Maastrichtian of Haţeg Basin, Romania, Acta Palaeontologica Polonica 50 (1), pp. 57-71 : 62-63

Becklesius nopcsai sp. nov.

Fig. 3G .

Holotype: PSMUBB V 361 , fragment of dentary with four complete teeth and two empty loci.

Type locality: Pui Islaz, Haţeg Basin, Transylvania, Romania, Europe.

Type horizon: Sânpetru Formation, Maastrichtian, Late Cretaceous.

Derivation of the name: After Baron Francis von Nopcsa, pioneer in palaeontological researches in Haţeg Basin.

Diagnosis.— Becklesius nopcsai differs from both Becklesius hoffstetteri and Becklesius cataphractus by having the apex of the labial cusp that is less developed in height, giving a square shape to the crown (whereas the crowns of B. hoffstetteri and B. cataphractus are more triangular); and by a wide lingual cusp reaching nearly 75% of the width of the labial cusp (whereas about 40% in both B. hoffstetteri and B. cataphractus ).

Material.—PSMUBB V 361, V 362 (two incomplete dentaries), V 363, V 364 (two incomplete maxillae).

Description.—The holotype PSMUBB V 361 is 3.7 mm long, with four complete teeth and two empty loci ( Fig. 3G 1 ). The Meckelian canal is open. The labial side of the dentary is smooth and bears a series of aligned foramina. Teeth are pleurodont, high, straight, slender, enlarged lingually in the middle of their height and they extend beyond the dental parapet for more than third of their height. The crowns are curved lingually and ornamented by vertical ridges. The teeth bear a wide and flattened lingual cusp (cuspis lingualis sensu Richter 1994) that extends nearly over 75% of the width of the labial cusp. The lateral borders of the crown are straight−sided and parallel ( Fig. 3G 2 ). The anguli mesialis and distalis (sensu Richter 1994) are pointed and reach nearly 90 degrees, and the labial cusp is nearly the same height as the anguli. The crown is therefore square−shaped. The mesial crest is slightly longer than the distal crest resulting in posterior displacement of the apex of the tooth crown that is displaced posteriorly ( Fig. 3G 2 ). Discussion.— Richter (1994) showed that the family Paramacellodidae is, e.g., characterised by strongly built teeth with crowns bearing a mesial crest longer than the distal one. In this family, only the genus Becklesius possesses robust, chisel−shaped teeth with the mesial crest always longer than the distal crest, pronounced angles between the lateral sides of the crown and the labial crests, and an additional lingual cusp ( Kosma 2003). In the type species, Becklesius hoffstetteri (see Seiffert 1973: fig. 18), this lingual cusp is about 40% of the width of the labial cusp. It is therefore distinctly narrower than on the specimens from Pui Islaz where the lingual cusp reach 75% of the width of the labial cusp. The lateral sides of the crowns are slightly curved to the apex, and the angles are more obtuse and not pointed, such that the crown appears triangular in lingual view ( Hoffstetter 1967). In B. cataphractus (see Richter 1994: fig. 9), the crests and the lateral sides of the crown are clearly separated by pointed angles like on the specimen from Pui Islaz. However, B. cataphractus possesses a narrow lingual cusp that represents about 40% of the width of the labial cusp. Moreover, this latter cusp is well−developed in height giving a triangular aspect to the crown whereas the crown of B. nopcsai is more square−shaped. We believe that these differences justify the erection of the new species Becklesius nopcsai for this Becklesius material recovered from Pui Islaz.

Figures

Fig. 3. A–E. Discoglossidae. A. PSMUBB V 356, cf. Eodiscoglossus sp., left ilium in lateral view. B, C. cf. Paradiscoglossus sp. B. PSMUBB V 357, great form, right ilium in lateral view. C. PSMUBB V 358, small form, left ilium in lateral view. D, E. Discoglossidae indet. D. PSMUBB V 353, urostyle in dorsal view. E. PSMUBB V 355 sacral vertebra in ventral view. F, G. Becklesius. F. PSMUBB V 365, B. cf. hoffstetteri, left dentary in lingual view. G. PSMUBB V 361, holotype of B. nopcsai sp. nov., fragment of left dentary (G1) and tooth crown (G2) in lingual view. SEM migrographs.

Fig. 1. The outcrop (Pui Islaz, indicated by a star) attributed to the Maastrichtian Sânpetru Formation, is located in the Bărbat River bed south of the village of Pui. The grey areas indicate the sedimentary basins (I, Rusca Montana Basin; II, Strei Basin; III, Haţeg Basin; IV, Petrosani Basin). Modified from Codrea et al. (2002).

Fig. 2. Albanerpeton sp. A. PSMUBB V 180, left premaxilla in lingual (A1) and labial (A2) views. B. PSMUBB V 195, right maxilla in lingual (B1) and labial (B2) views. C. PSMUBB V 237, left dentary in lingual (C1), labial (C2), and occlusal (C3) views. D. PSMUBB V 308, small fragmentary frontal in ventral (D1) and dorsal (D2) views. E. PSMUBB V 317, distal end of a left humerus in ventral view. F. PSMUBB V 328, atlas in anterior view. G. PSMUBB V 334, axis in dorsal view. SEM migrographs.