New Egypt Formation

The New Egypt Formation is a Late Cretaceous (Maastrichtian) geologic formation of the Monmouth Group in New Jersey, United States.

New Egypt Formation
Stratigraphic range: Maastrichtian ~
Type	Geological formation
Unit of	Monmouth Group
Underlies	Hornerstown Formation
Overlies	Navesink Formation
Lithology
Primary	Marl
Other	Sandstone, claystone
Location
Coordinates	40.3°N 74.1°W / 40.3; -74.1
Approximate paleocoordinates	37.9°N 41.5°W / 37.9; -41.5
Region	New Jersey
Country	USA
Type section
Named for	New Egypt, New Jersey
New Egypt Formation (the United States) New Egypt Formation (New Jersey)

Description

The basal New Egypt is a massive clayey, glauconitic marl that closely resembles the Navesink Formation into which it grades below. Ammonites and other invertebrates found at the Spheno Run 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 and Taphrosphys sulcatus; various bone elements from at least two species of mosasaurs including a sizable fragment of dentary bone from Prognathodon rapax and numerous shed teeth from Mosasaurus maximus.

Vertebrate remains also include material from sharks, particularly teeth and unusually large vertebral centra from an individual lamniform shark Squalicorax pristodontus, 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.

Vertebrate paleobiota

Cartilaginous fish

The following taxa are known:

Sharks

Sharks of the Hornerstown Formation
Genus	Species	Member	Location	Material	Notes	Images
Brachaelurus	B. hornerstownensis	Shrewsbury	Arneytown	1 tooth	A blind shark. Type locality for species.
Chiloscyllium	C. sp.	Shrewsbury	Arneytown	1 tooth	A bamboo shark.
Cretalamna	C. appendiculata	Shrewsbury	Arneytown	1 tooth	A megatooth shark.
Ginglymostoma	G. cuspidata	Shrewsbury	Arneytown	3 teeth	A nurse shark. Type locality for species.
Hemiscyllium	H. sp.	Shrewsbury	Arneytown	1 tooth	A bamboo shark.
Proheterodontus	P. creamridgensis	Shrewsbury	Arneytown	1 tooth	A bullhead shark. Type locality for species.
Pseudodontaspis	P. cf. herbsti	Shrewsbury	Arneytown	1 tooth	A sand shark.
Serratolamna	S. serrata	Shrewsbury	Arneytown	1 tooth	A serratolamnid mackerel shark.
Squalicorax	S. kaupi	Shrewsbury	Arneytown	1 tooth	A crow shark.
Squatina	S. hassei	Shrewsbury	Arneytown	4 teeth	An angelshark.

Rays

Rays of the Hornerstown Formation
Genus	Species	Member	Location	Material	Notes	Images
Dasyatis	D. newegyptensis	Shrewsbury	Arneytown	3 teeth	A whiptail stingray. Type locality of species.
Protoplatyrhina	P. renae	Shrewsbury	Arneytown	1 tooth	A hypsobatid ray.
Ptychotrygon	P. sp.	Shrewsbury	Arneytown	1 tooth	A ptychotrygonid sawskate.
Rhinobatos	R. casieri	Shrewsbury	Arneytown	2 teeth	A guitarfish.
Rhombodus	R. binkhorsti	Shrewsbury	Arneytown	2 teeth	A rhombodontid ray.
	R. laevis			1 tooth
Sclerorhynchus	S. pettersi	Shrewsbury	Arneytown	2 rostra pieces	A sclerorhynchid sawskate.

Other fossils

Bivalves

• Cucullaea vulgaris

Cephalopods

• Baculites ovatus

Fish

• Leptomylus forfex
• Edaphadon mirificus

Reptiles

• Agomphus pectoralis
• Catapleura repanda
• Dryptosaurus aquilunguis
• Hadrosaurus minor
• Hyposaurus rogersii
• Mosasaurus dekayi
• Mosasaurus hoffmanni
• ?Hadrosauridae indet.
• Lambeosaurinae indet. [1]
• Hadrosauromorpha indet.

See also

• Paleontology in New Jersey

References

Bibliography

• Carter, M. T. W.; Johnson, R. O.; Chamberlain, J. A.; Mehling, C. (2008), "A new vertebrate fauna from the Late Cretaceous (Maastrichtian) New Egypt Formation of New Jersey", Abstracts with Programs - Geological Society of America, 40: 78–79

Further reading

• Brownstein, Chase Doran (2021), "Osteology and phylogeny of small-bodied hadrosauromorphs from an end-Cretaceous marine assemblage", Zoological Journal of the Linnean Society, 191: 180–200, doi:10.1093/zoolinnean/zlaa085
• B. Stahl and D. Parris. 2004. The complete dentition of Edaphodon mirificus (Chondrichthyes: Holocephali) from a single individual. Journal of Paleontology 78(2):388-392
• W. B. Gallagher. 1993. The Cretaceous/Tertiary mass extinction event in the North Atlantic coastal plain. The Mosasaur 5:75-154
• W. B. Gallagher. 1984. Paleoecology of the Delaware Valley region. Part II: Cretaceous to Quartenary. The Mosasaur 2:9-43
• E. S. Gaffney. 1975. A revision of the side-necked turtle Taphrosphys sulcatus (Leidy) from the Cretaceous of New Jersey. American Museum Novitates (2571)1-24
• E. L. Troxell. 1925. Hyposaurus, a marine crocodilian. American Journal of Science 9:489-514
• G. R. Wieland. 1905. Structure of the Upper Cretaceous turtles of New Jersey: Agomphus. The American Journal of Science, series 4 20:430-444
• G. R. Wieland. 1904. Structure of the Upper Cretaceous turtles of New Jersey: Lytoloma. The American Journal of Science, series 4 18:183-196
• E. D. Cope. 1875. The Vertebrata of the Cretaceous formations of the west. Report of the United States Geological and Geographical Survey of the Territories 2:1-303
• E. D. Cope. 1870. Synopsis of the Extinct Batrachia, Reptilia and Aves of North America. Part II. Transactions of the American Philosophical Society, New Series 14:105-235
• E. D. Cope. 1866. [On the remains of a gigantic extinct dinosaur, from the Cretaceous Green Sand of New Jersey]. Proceedings of the Academy of Natural Sciences of Philadelphia 18:275-279