Pteroscyllium undetermined

Kriwet, Jürgen, Nunn, Elizabeth V. & Klug, Stefanie, 2009, Neoselachians (Chondrichthyes, Elasmobranchii) from the Lower and lower Upper Cretaceous of north-eastern Spain, Zoological Journal of the Linnean Society 155 (2), pp. 316-347 : 323-324

PTEROSCYLLIUM SP. ( FIG. 5A–D )

Material: A fragmentary tooth, MPZ 2005-07. An isolated main cusp; MPZ 2005-8.

Occurrence: Sample 3 from shallow lake settings (facies 1b) of the lower Aguilón Formation, lower Barremian, Aguilón.

Description: The crown consists of a high and slender main cusp that is bent lingually and a single preserved lateral cusplet. In profile view, the main cusp is slightly sigmoidal. The cutting edge of the main cusp and lateral cusplets is prominent and continuous. It does not extend to the apex. The cusplets are in the same plane as the main cusp in profile view. The lateral cusplet is broad and high, and separated from the main cusp. The labial ornamentation is strong and well spaced, with folds originating at or shortly by a broad and deep notch over the crown/ root junction, and extending to the half of the apex. Some folds bifurcate near the base. The lingual ornament is weaker, consisting of fine ridges bifurcating at the base of the main cusp and cusplets. The lingual ridges extend to contact with the neck, which is very broad. The crown overhangs the root. The root is poorly preserved with the lobes missing. There are a pair of margino-lingual foramina, which is well marked. The vascularization seems to be of the holaulacorhize-type.

The single isolated cusp is triangular and bent distally. In profile view, it is slightly sigmoidal with a prominent cutting edge that does not reach the apex. The ornamentation is similar to the specimen described above.

Remarks: The overall morphology of this species is very similar to that of Pteroscyllium , which is readily recognized by the increased lingual orientation of the cusplets relative to the main cusp, strong labial ornamentation and well-developed cutting edges. Neither known species of Pteroscyllium , however, has labial folds that originate so obviously above the crown base as seen here. The teeth of Palaeoscyllium from the Upper Jurassic of southern Germany ( Kriwet & Klug, 2004) and Lower Cretaceous of Poland ( Rees, 2005) have delicate and high central and lateral cusps with stronger ornamentation than found in Pteroscyllium . The state of preservation of the Spanish specimens unfortunately prevents a specific identification.

FAMILY SCYLIORHINIDAE INDET. ( FIG. 5E–Q )

Material: Six fragmentary teeth, MPZ 2005-09. Occurrence: Sample 4 from floodplain environments with channel deposits (facies 2) of the lower part of the Mosqueruela Formation (lower Cenomanian), Aliaga.

Description: All teeth are presumed to come from posterior positions. They have low and broad crowns, with folds that are very strong and extend far up the crown. Where a complete tooth crown is present, there is one pair of poorly developed lateral cusplets that are broadly united to the main cusp, which is broad and rounded. Some specimens have a more heavily ornamented labial face, others a more heavily ornamented lingual face. The folds tend to bifurcate at the base of the labial and/or lingual face of the central cusp. The root is damaged or absent in all specimens.

Remarks: These specimens are unlikely all to belong to the same species or even genus of Scyliorhinidae . However, due to the isolated and fragmented nature of the teeth, in particular the lack of root structure, it is impossible to identify them beyond family level.

SUPERORDER BATOMORPHII CAPPETTA, 1980 B

ORDER RAJIFORMES BERG, 1940

SUBORDER RHINOBATOIDEI FOWLER, 1941

FAMILY RHINOBATIDAE MÜLLER & HENLE, 1838

Figures

Figure 5. A–D, Pteroscyllium sp. A–D, lateral tooth. A, labial view. B, lateral view. C, lingual view. D, occlusal view. E–Q, Scyliorhinidae indet. E–I, lateral (?) tooth crown. E, labial view. F–G, lateral views. H, lingual view. I, occlusal view. J–M, posterior (?) tooth. J, labial view. K, lateral view. L, lingual view. M, occlusal view. N–Q, posterior (?) tooth. N, labial view. O, lateral view. P, lingual view. Q, occlusal view. All scale bars equal 0.5 mm.