Premontreia (Oxyscyllium), 1997

Cicimurri, David J. & Knight, James L., 2019, Late Eocene (Priabonian) elasmobranchs from the Dry Branch Formation (Barnwell Group) of Aiken County, South Carolina, USA, PaleoBios 36, pp. 1-31 : 16

PREMONTREIA (OXYSCYLLIUM) SP.

CF. PR. (O.) GILBERTI ( CASIER, 1946)

FIG. 5H–N

Material examined —SC2013.38.29, tooth ( Fig. 5H, I ); SC2013.38.30, tooth ( Fig. 5J–L ); SC2013.38.31, tooth ( Fig. 5M, N ); SC2013.38.32, tooth; SC2013.38.33, tooth; SC2013.38.34, incomplete tooth.

Remarks —The root morphology of our six specimens leads us to assign the teeth to Premontreinae Cappetta, 1992, which currently contains the genera Premontreia and Pachyscyllium Reinecke and others, 2005. Noubhani and Cappetta (1997) have since divided Premontreia into two subgenera: Premontreia and Oxyscyllium. Although only the dentine core of the Dry Branch Formation specimens is preserved, we can discern that the tooth crowns bore coarse basal longitudinal ridges and they were distally inclined, which is in contrast to what is seen on teeth of the various Oligocene to Pliocene species of Pachyscyllium that have been described ( Cappetta, 1970, Reinecke and others 2005, Haye et al. 2008, Reinecke et al. 2008). With respect to crown shape, the Dry Branch Formation teeth are identifiable to the subgenus Premontreia (Oxyscyllium) Noubhani and Cappetta, 1997 because of the large and well differentiated lateral cusplets. Additionally, we believe that the teeth compare favorably to Pr. (O.) gilberti , a species formerly placed within Scyliorhinus ( Casier 1946, Bor 1985, Nolf 1988, Kemp et al. 1990, Case et al. 1996, also Reinecke et al. 2008). We also consider specimens that Parmley and Cicimurri (2003) identified as Scyliorhinus gilberti and material identified as Scy. distans (Probst, 1879) by Manning and Standhardt (1986:fig. 1, no. 2) to be conspecific with the Dry Branch taxon.

Figures

Figure 5. Scyliorhinid shark teeth from the Dry Branch Formation (Priabonian) of Aiken County, South Carolina. A–G. Foumtizia sp. Anterior tooth in labial (A), lingual (B) and profile (C) views, SC2013.38. 27. Anterior tooth in labial (D) view, SC96.97.5. Anterior tooth in labial (E) view, SC96.97.6. Anterior tooth in labial view (F), SC96.97.7. Anterior tooth in labial view (G), SC 96.97.8. H–N. Premontreia (Oxyscyllium) sp. cf. Pr. (O.) gilberti. Anterior tooth in labial (H) and distal (I) views, SC2013.38.29. Labial at left in I. Anterior? tooth in labial (J), lingual (K) and basal (L) views, SC2013.38.30. Lateral tooth in labial (M) and lingual (N) views, SC2013.38.31. O–CC. Scyliorhinus sp. Lateral tooth in labial (O), lingual (P), occlusal (Q), and basal (R) views, SC2013.38.36. An- terolateral tooth in basal (S) view, SC2013.38.35. Lateral tooth in labial (T), lingual (U), and occlusal (V) views, SC2013.38.39. Lateral tooth in labial (W), lingual (X), and occlusal (Y) views, SC2013.38.37. Lateral tooth in labial (Z), lingual (AA), and occlusal (BB) views, SC2013.38.38. Anterior? tooth in occlusal (CC) view, SC2013.38.40. Labial at top in L, R, S; at bottom in Q, V, Y, BB, CC. Scale bars=1mm.