Horsehead Cliffs, Zone 12-13 (Miocene of the United States)

Also known as Westmoreland State Park

Where: Westmoreland County, Virginia (38.2° N, 76.9° W: paleocoordinates 38.4° N, 73.6° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Plum Point Member (Calvert Formation), Langhian (16.0 - 13.8 Ma)

• Peritresius virginianus type specimen is from "about four feet above the beach level" and the other fossils are from "about seven feet" above it. Author lists this cliff as having exposures of Calvert, Choptank and St. Mary's Formations

• group of beds-level stratigraphic resolution

Environment/lithology: estuary or bay; diatomaceous, gray, blue claystone

• sparse molluscs, low in diversity; subtropical environment in embayment and dry onshore; area not far from shore
• blue-gray diatomaceous clay

Size class: macrofossils

Collected by C. T. Berry, W. G. Lynn in 1935; reposited in the USNM

Primary reference: C. T. Berry. 1937. More complete remains of a chelonian, Syllomus crispatus Cope, from the Miocene of Virginia. American Museum Novitates 953:1-19 [J. Alroy/E. Leckey/E. Leckey]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 28368: authorized by John Alroy, entered by Erin Leckey on 10.02.2003, edited by Mark Uhen

Creative Commons license: CC BY (attribution)

Taxonomic list

• referred P. virginianus specimen is from "about 0.4 mile south" of the type locality
Aves
 Charadriiformes - Alcoidae
Miocepphus mcclungi4 Wetmore 1940 auk
Reptilia
 Crocodylia -
Thecachampsa antiquus3 Leidy 1852 crocodilian
 Testudines - Cheloniidae
Syllomus crispatus, "Peritresius virginianus n. sp." = Syllomus aegyptiacus1
Syllomus crispatus Cope 1896 sea turtle
"Peritresius virginianus n. sp." = Syllomus aegyptiacus1 Lydekker 1899 sea turtle
Mammalia
 Carnivora - Phocidae
"Leptophoca lenis" = Leptophoca proxima2
"Leptophoca lenis" = Leptophoca proxima2 Van Beneden 1876 seal
 Cetacea - Eurhinodelphinidae
cf. Eurhinodelphis sp.2 Van Beneden and Gervais 1880 toothed whale