Dasyatis rugosa (Probst, 1877)

Cicimurri, David J. & Knight, James L., 2009, Late Oligocene sharks and rays from the Chandler Bridge Formation, Dorchester County, South Carolina, USA, Acta Palaeontologica Polonica 54 (4), pp. 627-647 : 638-639

Dasyatis rugosa (Probst, 1877)

Fig. 8C .

Referred specimens.—BCGM 9098 and 9099, SC 2009.18.18.

Comments.—Although crown ornamentation is somewhat similar to Dasyatis cavernosa , D. rugosa is slightly larger (2.5 mm in width) and has a more convex labial face, wide but indistinct transverse crest, often sinuous labial crown margin (in basal view), and more robust root lobes (see also Cappetta 1970; Reinecke et al. 2005; Haye et al. 2008).

Stratigraphic and geographic range.—Oligocene (Chattian), USA (South Carolina); Miocene, France, Germany, Portugal, Poland.

Dasyatidae gen. et sp. indet.

Fig. 8D .

Referred specimens.—BCGM 9100 and 9101, SC 2009.18.19.

Comments.—These teeth are very easily distinguished from Dasyatis in our sample, not just by their larger size (3.5 mm in width), but by the nearly complete absence of crown ornamentation. There is a sharp transverse crest that divides the crown into a small, weakly concave labial face and a much more lingually expanded lingual face, and the labial crown margin (in basal view) is virtually straight.

Although this morphology was not discussed by Purdy et al. (2001), we have personally observed identical teeth from North Carolina (Lee Creek). These teeth are comparable to Dasyatis serralheiroi Cappetta, 1970 from the French Miocene, as well as to smooth or weakly ornamented teeth from the German and Swiss Miocene thought to be female D. cavernosa (Probst, 1877) (i.e., Leriche 1927; Bracher 2005; Wienrich and Reinecke 2009). Additionaly, the morphology is akin to teeth of extant Himantura Müller and Henle, 1837 (see Compagno and Roberts 1982; Monkolprasit and Roberts 1990), a taxon known primarily from the Pacific realm in freshwater and marine environments ( Bonfil and Abdallah 2004).

CICIMURRI AND KNIGHT—OLIGOCENE SHARKS FROM SOUTH CAROLINA 639

Figures

Fig. 8. Stingrays from Summerville, upper Chattian. A. Dasyatis cavernosa (Probst,1877), BCGM 9097, occlusal (A1) and labial (A2) view. B. D. cf. cavernosa, BCGM 9103, male tooth, occlusal (B1) and labial (B2) view. C. D. rugosa (Probst, 1877), BCGM 9099, occlusal (C1) and labial (C2) view. D. Dasyatidae gen. et. sp. indet., BCGM 9101, occlusal (D1), labial (D2), and lateral (D3) view. E. BCGM 9106, Dasyatis sp. denticle, lateral−oblique view.