THE CRETACEOUS OF NORTH CAROLINA: A COMPARISON OF TWO BONEBEDS

The discovery of a fossil bonebed near Elizabethtown, Bladen County, North Carolina, has contributed to an updated late Cretaceous (Campanian) age faunal list. This data verifies previous paleoenvironmental interpretations as well as indicates latitudinal paleobiogeographic extensions of species previously restricted to other Atlantic and Gulf Coast localities. The Elizabethtown bonebed also permits a faunal comparison, correlation, and depositional interpretation with that of Phoebus Landing, a bonebed located approximately 6km away.

During the Campanian, a fluvially-dominated estuarine system preserved vertebrate elements from a multitude of organisms in a ca. 10 cm thick bonebed at what is now the Elizabethtown locality. This bonebed stratigraphically lies at the top of the Bladen Formation of the Black Creek Group. Comparisons of the Elizabethtown bonebed to that of Phoebus Landing yield greater abundance and diversity of vertebrate material. This is interpreted to be the result of geologic processes acting upon and subjecting the bonebeds to variant depositional scenarios. Dominating the vertebrate fossils recovered from Phoebus Landing are highly abraded, oxidized, robust, dense elements suggestive of successive entrainment and reworking of the bonebed. The Elizabethtown bonebed on the other hand, is comprised of a greater abundance of small, fragile, elements exhibiting little or no abrasion, implying a short transport duration and distance from the source area. Although both bonebeds yield a diverse assemblage of fresh water, euryhaline, stenohaline, and terrestrial organisms, (including bony fishes, sharks, turtles, squamates, crocodyliforms, and dinosaurs), their abundance and preservation conditions are different.