ALBEMARLE SOUND NC - A MODERN ANALOG FOR THE ELLISDALE FOSSIL SITE (LATE CRETACEOUS, CAMPANIAN, NJ)

The Ellisdale Fossil Site in the valley of the Crosswicks Creek in Monmouth County, New Jersey, has produced the largest and most diverse fauna of Late Cretaceous terrestrial animals from eastern North America to date, including the type specimens of the teiid lizard Prototeius stageri and the batrachosauroidid salamander Parrisia neocesariensis. The site occurs within the basal portion of the Marshalltown Formation, and dates from the Campanian Stage of the Late Cretaceous Period.

Taphonomic analysis of the Ellisdale fauna has revealed two distinctly different types of preservation. Bones of both open water marine and far-upland terrestrial animals are typically broken, heavily worn, and missing the outermost layer of bone (periosteal layer or cortex of compact bone). In contrast, the bones of microvertebrate animals such as amphibians and lizards are much more complete, with delicate processes and the cortex of compact bone intact. The microvertebrate fauna of the site probably represents a "proximal" assemblage that lived at or near the final point of deposition, while the heavily worn bones represent a "distal" fauna. In addition, disarticulated but well-preserved bones of turtles and crocodilians are also a significant component of the proximal assemblage. Overall, these data suggest that the Ellisdale Site may preserve the sediments and fossils present in a tidal freshwater estuarine or fluvio-deltaic environment. This contention is supported by a palynological study of the site, which identified large quantities of well-preserved pollen indicative of a freshwater terrestrial plant assemblage. A similar environment is found today in the back-bays and estuaries of the northern Outer Banks of North Carolina, in particular the Albemarle Sound. Many of the bony fish taxa present at Ellisdale as fossils are still found in these environments today, along with lizards, salamanders and frogs that occupy similar niches to their Cretaceous counterparts.