Roulletia bureaui, Vullo & Cappetta & Néraudeau, 2007
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publication ID |
https://doi.org/ 10.5281/zenodo.13741981 |
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persistent identifier |
https://treatment.plazi.org/id/03A787AC-165B-FFA0-F15C-8799CB69F84E |
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treatment provided by |
Felipe |
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scientific name |
Roulletia bureaui |
| status |
gen. et sp. nov. |
Roulletia bureaui gen. et sp. nov.
Fig. 3A–G View Fig .
Derivation of the name: Species named after Mr. Michel Bureau, the amateur palaeontologist who collected the material.
Holotype: Specimen UM AMA 6 .
Paratypes: Specimens UM AMA 3–5 , UM AMA 7–9 .
Type locality: L’Amas quarry, Roullet–Saint−Estèphe, Charente.
Type horizon: Upper Cenomanian, unit D, lithological level Dm.
Material.—Seven teeth. Only known from the type locality.
Diagnosis.—Same as for genus.
Description.—The holotype (UM AMA 6; Fig. 3D View Fig ) is a lateral tooth, 10 mm high and distally inclined. The smooth crown is relatively narrow, and displays a pair of small cusplets. A second, minute cusplet, can be observed distally. The labial face is slightly swollen. The root is asymmetrical, with a distal lobe stronger than the mesial one. The basilar notch of the root is angular. The lingual protuberance is very developed, and is marked by a deep and relatively broad groove. One of the paratypes (UM AMA 9; Fig. 3G View Fig ) is an anterior tooth, 9 mm high. It is almost symmetrical, with an erect, sharp cusp, and slightly concave edges. The crown is devoid of ornamentation, and shows convex labial and lingual faces. It bears one pair of very reduced but sharp, acute, marginal cusplets. The root is rather thick, with strong lobes separated by an angular notch. Some specimens, like UM AMA 7 ( Fig. 3E View Fig ), display a rounded root notch.
Remarks.—Among odontaspidids, the more reminiscent species is “ Carcharias ” amonensis (mainly for some teeth of antero−lateral files), whose very distinctive teeth have been found in association with the teeth of Roulletia bureaui gen. et sp. nov. in the type locality. So, one could question about the separation of the two taxa at the generic level. Yet, a close study of the material allows us to reject this possibility. In R. bureaui gen. et sp. nov., the cutting edge of the crown is in continuity between the cusp and the lateral cusplets, as well in the anterior as in the lateral files. The cusplets are minute and not duplicated, and the root is rather thick with a deep groove. In “ C.” amonensis, in the anterior and antero−lateral files, the teeth lack cutting edges at the base of the cusp and of the cusplets. The teeth of “ C. ” amonensis have one to three pairs of lateral cusplets, generally more developed. They are also more labio−lingually compressed, and the crown displays a flatter labial face. The root is more expanded transversally and more flattened labio−lingually ( Cappetta and Case 1975; Landemaine 1991). The association of these morphological features allows to separate R. bureaui gen. et sp. nov. and “ C.” amonensis at the generic level. It must be also noted that teeth of R. bureaui gen. et sp. nov. have never been collected in localities where “ C.” amonensis is abundant, as for instance in the Cenomanian of Texas or in the locality of “Les Renardières”, at Tonnay−Charente. Therefore, R. bureaui gen. et sp. nov. cannot be considered as a scarce morphological variation of “ C.” amonensis.
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