Spheno Run (Cretaceous of the United States)

Where: Monmouth County, New Jersey (40.3° N, 74.1° W: paleocoordinates 37.9° N, 41.5° W)

When: New Egypt Formation (Monmouth Group), Late/Upper Cretaceous (100.5 - 66.0 Ma)

Environment/lithology: terrestrial; massive, glauconitic marl

• The basal New Egypt is a massive clayey, glauconitic marl that closely resembles the Navasink Formation into which it grades below.

Size class: macrofossils

• Additionally, ammonites and other invertebrates found at this site correlate well with the middle Severn Formation of Maryland. Spheno Run has so far produced a remarkable number of vertebrate specimens, especially from marine reptiles, including: carapace elements from at least two species of turtles, Peritresius ornatus (Leidy, 1856) and Taphrosphys sulcatus (Leidy, 1856); various bone elements from at least two species of mosasaurs including a sizable fragment of dentary bone from Prognathodon rapax (Hay, 1902) and numerous shed teeth from Mosasaurus maximus (Cope, 1869). Vertebrate remains also include material from sharks, particularly teeth and unusually large vertebral centra from an individual lamniform shark Squalicorax pristodontus (Agassiz, 1843), bony fish, and, rarely, dinosaurs. In addition to the vertebrate collection, Spheno Run also yields an abundance of invertebrate species including: twenty-two bivalves, seven gastropods, six cephalopods, and one each of echinoidea, porifera, and scaphopoda. It is rare to find such an extensive array of both vertebrate and invertebrate species within one horizon in New Jersey. This site presents an exciting opportunity to study the full-spectrum of Late Cretaceous paleoecology as expressed in the basal New Egypt Formation

Primary reference: M. T. W. Carter, R. O. Johnson, J. A. Chamberlain and C. Mehling. 2008. A new vertebrate fauna from the Late Cretaceous (Maastrichtian) New Egypt Formation of New Jersey. Abstracts with Programs - Geological Society of America 40(2):78-79 [M. Uhen/M. Shalap/M. Shalap]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 127082: authorized by Mark Uhen, entered by Margaret Shalap on 24.04.2012

Creative Commons license: CC BY (attribution)

Taxonomic list

 Lamniformes - Anacoracidae
Squalicorax pristodontus Agassiz 1843 crow shark
 Testudines - Pancheloniidae
Peritresius ornatus Leidy 1856 turtle
 Testudines - Bothremydidae
Taphrosphys sulcatus Leidy 1856 sideneck turtle
 Squamata - Mosasauridae
"Mosasaurus maximus" = Mosasaurus hoffmanni, Prognathodon rapax
"Mosasaurus maximus" = Mosasaurus hoffmanni Mantell 1829 mosasaur
Prognathodon rapax Hay 1902 mosasaur