Pungo River Formation

The Pungo River Formation is divided into two members, the Early Miocene-aged Belhaven Member and the Middle Miocene-aged Bonnerton Member. It stretches from southern North Carolina north to southeastern Virginia, being replaced northwards by the roughly coeval Calvert Formation.^[1] However, it largely lies buried underground throughout much of this range, generally at depths of 120 to 170 feet (37 to 52 m) below the surface.^[2] The only major terrestrial exposure is at the Aurora mine, although offshore exposures are also known on the continental shelf of Onslow Bay, which were likely redeposited via sea-level changes over the Pliocene and Pleistocene.^[3]

The deposition of the Pungo River Formation is thought to be linked to a major marine transgression from the Mid-Miocene Climactic Optimum, which inundated the Onslow and Aurora embayments.^[3] Deposition of the Pungo River Formation would have ended following a recession of the sea level, exposing more land. Later, the ocean would have again submerged the land, depositing the Yorktown Formation over it.^[2]

The highly fossiliferous and phosphorus-rich deposits in Beaufort County, which are now mined, are thought to have been formed by a large back eddy that formed behind a predecessor to Cape Lookout. The eddy would have caught many marine organisms that used up all the dissolved oxygen in the water, forming a large dead zone that allowed organic materials to easily fossilize due to the lack of decomposition.^[3]

Based on the Paleobiology Database except where noted:^[4][5]

Cartilaginous fish

Based on Purdy et al.. (2001):^[6]

More information Genus, Species ...

Genus	Species	Notes	Images
Aetobatus	A. sp.	An eagle ray.
Alopias	A. cf. superciliosus
	A. cf. vulpinus	A thresher shark, potentially the modern common thresher.
Carcharhinus	C. brachyurus
	C. falciformis
	C. leucas
	C. perezi
	C. plumbeus
	C. priscus	An extinct requiem shark.
Carcharias	C. acutissimus	An extinct sand tiger shark.
	C. sp.	A relative of the sand tiger shark.
Carcharodon (=Cosmopolitodus)	C. hastalis	A mackerel shark related to the modern white shark.
Carcharoides	C. catticus	A mackerel shark. Teeth formerly assigned to Triaenodon obesus.[7]
Cetorhinus	C. sp.	A relative of the basking shark.
Chaenogaleus	C. affinis	An extinct relative of the hooktooth shark.
Dasyatis	D. cf. americana	A stingray similar to the modern southern stingray.
Echinorhinus	E. cf. blakei	An extinct bramble shark.
Galeocerdo	G. aduncus[3]	An extinct relative of the tiger shark.
Ginglymostoma	G. sp.	A nurse shark.
Hemipristis	H. serra	An extinct relative of the snaggletooth shark.
Hypogaleus	H. sp.	A relative of the blacktip tope.
Isurus	I. oxyrinchus	The modern shortfin mako shark.
Megachasma	M. sp.	A relative of the megamouth shark.
Megalolamna	M. paradoxodon[8]	A mackerel shark.
Megascyliorhinus	M. miocaenicus	A catshark.
Mobula	M. sp.	A devil ray.
Mustelus	M. sp.	A smooth-hound.
Negaprion	N. brevirostris	The modern lemon shark.
Notorynchus	N. cepedianus	The modern broadnose sevengill shark.
Odontaspis	O. cuspidata	An extinct sand shark.
	O. ferox	The modern deepwater sand tiger.
Otodus	O. chubutensis	A megatooth shark.
	O. megalodon	A megatooth shark, the megalodon.
Paragaleus	P. sp.	A weasel shark.
Physogaleus	P. contortus	A requiem shark.
Plinthicus	P. stenodon	A devil ray.
Pristiophorus	P. sp.	A sawshark.
Pteromylaeus	P. sp.	An eagle ray.
Rhincodon	R. sp.	A relative of the whale shark.
Rhinobatos	R. sp.	A guitarfish.
Rhinoptera	R. sp.	A cownose ray.
Rhizoprionodon	R. sp.[3]	A sharpnose shark.
Scyliorhinus	S. sp.	A catshark.
Sphyrna	S. cf. media	A hammerhead shark, potentially the modern scoophead.
	S. zygaena	The modern smooth hammerhead.
Squatina	S. sp.	An angelshark.

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Reptiles

More information Genus, Species ...

Genus	Species	Notes	Images
Bairdemys	B. miocenica	A marine side-necked turtle.[11]
Thecachampsa	T. antiqua	A gavialoid crocodilian.[12]

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Birds

Based on Olson & Rasmussen (2001):^[13]

More information Genus, Species ...

Genus	Species	Notes	Images
Anatidae indet.		A waterfowl of uncertain affinities.
Ardenna	A. aff. gravis	A shearwater similar to the modern great shearwater.
?Balearica	?B. sp.	A crane, potentially a crowned crane.
Ciconia	C. sp.	A stork.
Ciconiidae indet.		A stork of uncertain affinities.
?Colymboides	?C. sp.	A potential early loon.
Gavia	G. egeriana	A loon.
Galliformes indet.		A landfowl of uncertain affinities.
Heliornis	H. aff. fulica	A finfoot similar to the modern sungrebe. The only fossil record of the family.[14]
Larus	L. sp.	A gull.
Miocepphus	M. mcclungi	An early auk. Type locality for M. mergulellus. Stratigraphy uncertain, but most likely belongs to the Pungo River Formation due to the genus being largely restricted to the Miocene.[15]
	M. mergulellus[15]
Morus	M. atlanticus	An extinct gannet.
	M. loxostyla
?Ortalis	?O. sp.	A potential chachalaca.
Phasianidae indet.		A small indeterminate galliform about the size of a mountain quail.
Puffinus	P. sp.	A shearwater.
Rallidae indet.		A rail of uncertain affinities.

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• List of fossiliferous stratigraphic units in North Carolina