Also see Dasyatis genus page

In the Upper Cretaceous, a second order of batoids appears in the fossil record, the Myliobatiformes. This order includes three superfamilies and encompasses many common representatives of the Lee Creek fauna -- the Dasyatoidea (stingrays), Myliobatoidea (eagle and cow-nose rays) and Mobuloidea (devil rays). Cappetta (1987) suggests that these rays evolved in the above listed order, so this series will follow this sequence and present the stingrays, specifically the family DASYATIDAE, first.

The teeth are small and arranged in numerous files. Females have a crushing, and males often a clutching, dentition. Many of the challenges encountered with skate teeth are relived with the dasyatids. The number of extant species is fewer, but there seems to be significantly less research material available. Based upon current endeavors, the challenges appear to include: tooth position, sexual dimorphism, and variations within the species.

Relatively few fossil species have been described, and some may be better ascribed to the generic paleontological genus "Dasyatis" rather than the true genus as would be reflected by an extant species. From personal experience, I have collected over a thousand dasyatoid teeth from the mine and the DPW site. Although I currently feel that two families and four or five species are represented, well over 800 of the teeth are currently assigned to (lumped in) a group called type-H. If I were to segregate these teeth (which I have in part) by characteristics (crown design, foramina, ornamentation, uvula shape, surface structure, etc.), I could come up with fifty to a hundred tooth types. With a reasonably good sample and general adversity to "splitting," these are currently being treated as a variation of one or two "Dasyatis" species.

Potential Lee Creek Stingrays

As was done with the skates, it would be useful to look at the extant species of the western Atlantic for potential stingray species that might be represented at Lee Creek, particularly in the Yorktown. As previously discussed, the Pungo River Formation is thought to have been a subtropical environment and the Yorktown, warm temperate. Stingrays are a common element of the batoid fauna in the Pungo River and Yorktown which corresponds well with their warm water preference. The Bigelow & Schroeder (1948) inventory included four likely candidates: Dasyatis americana HILDEBRAND & SCHROEDER, 1928, D. centroura (MITCHILL), 1815, D. sabina (LESUER), 1824, and D. sayi (LESUER), 1817.

Cappetta (1970) lists six Miocene species of the eastern Atlantic. These could certainly be potential Lee Creek donors but no decisions have yet been made. These species include: Dasyatis cavernosa (PROBST), 1877, D. probsti CAPPETTA 1970, D. serralheiroi CAPPETTA. 1970. D. rugosa (PROBST), 1877, D. minuta CAPPETTA, 1970, and D. delfortriei CAPPETTA, 1970.

Lee Creek Stingray Teeth

As a percentage of the non-myliobatoid ray teeth recovered, stingray teeth are insignificantly more common in the Pungo River (41.5%) than the Yorktown (37.5%) tailings in the mine, reflecting a less temperature sensitive group of rays.

To obtain specimens, the best bet would be Blount Crossroads. The general lack of fine (under 2.0 mm) material at the DPW site has two skewing influences on these batoid teeth. First, the average size is greater at the DPW site and second, the relative abundance of dasyatoid teeth is much greater (accounting for 85% of the recovered ray teeth).

Those thought to be dasyatid have been broadly separated by the author into three type-groups: "H" (medium-sized with labio-lingual ridges on the transverse crest), "M" (lacking said ridges) and "O" (other).

H-Type Teeth. (Figures 1 & 2) When working DPW material or examining small teeth obtained directly from the mine, this is the most abundant batoid tooth type. There are variations of these teeth, but the illustrated examples should correspond in most cases with the majority of recovered material. Characteristics of these teeth compare well with those of extant Dasyatis teeth.

Although twelve sub-types have been established to account for male (7) and female (5) H-type teeth, I don't think that they represent more than two species, and would not be surprised if these are all variations of a single species.

Female teeth are usually 2.0 - 3.0 mm in width (combining DPW samples and those from the mine) and have a bilobate root with a globular crown. Contrary to the illustration, it is most common for there to be a single central foramen with no lateral foramina on the lobes. The lingual face has a median ridge and concave lateral faces. The labial face has a pitted appearance resulting from numerous intersecting enameloid ridges. A transverse ridge is prominent, its lingual face having numerous labio-lingually oriented ridges. Labially, it adjoins a transverse depression which can be weak to strong; lingually, there is a single uvula, but in some specimens when viewed occlusally, it may appear split or notched into two.

Male teeth have a bilobate root with a high cusp. They retain the pitted ornamentation on the labial face, but the labio-lingual ridges of the lingual face of the transverse crest are not present. This last characteristic is important when judging certain lateral and posterior teeth which may have a reduced cusp. On the labial face of the larger cusped teeth, there is often a median depression running down the cusp. This area may be ornamented with elongated enameloid ridges.

Fig. 1) "Dasyatis" sp Type "H" - [95-JAB-BC-501-S27] - female

Fig. 2) "Dasyatis" sp Type "H" - [96-JAB-TGA-432-S01] - male