Nomini Cliffs, Zone 14-16 (Miocene of the United States)

Where: Westmoreland County, Virginia (38.2° N, 76.8° W: paleocoordinates 38.4° N, 73.5° W)

• coordinate estimated from map

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

• Age after Kellogg (1968), but see (Marx & Fordyce below. Marx and Fordyce follow Case (1904) in suggesting that Metopocetus durinasus is from the St Marys Formation, but this seems unsubstantiated. Kellogg (1968) clearly states that this fossil is from Nomini Cliffs, which only exposes Zones 14-16, which are Langhian in age.

•USNM 8518 was collected from “a Miocene marl from near the mouth of the Potomac river” [90: 143]. Subsequent authors interpreted this description of the type locality to refer to either the Calvert Formation [93, 163] or the St. Mary‟s Formation [164], implying either a Langhian or a Serravallian age, respectively. To date, no other cetotheriid remains from the Calvert Formation have been described, but at least two cetotheriids (Cephalotropis coronatus and “Cetotherium” megalophysum; see above) occur in the Little Cove Point Member of the St Mary‟s Formation. This, together with the fact that the suggestion of the St Mary‟s formation as a potential source unit was published just eight years after the original description of the species, might support the origin of M. durinasus from the Little Cove Point Member. The latter has been strontium dated to the early Tortonian (11.7–10.0 Ma) [48, 49], which is the age assumed here pending the emergence of better-constrained occurrence data. (Marx & Fordyce, 2015).

• group of beds-level stratigraphic resolution

Environment/lithology: foreshore; brown, yellow, sandy claystone

• sparse molluscs, low in diversity; subtropical environment in embayment and dry onshore; area not far from shore, bay, short-term eustatic transgression events, long-term regression trend

Size class: macrofossils

Primary reference: M. D. Uhen. 2007. USNM Chesapeake Group Cetacean Collection Data. [M. Uhen/M. Uhen]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 71798: authorized by Mark Uhen, entered by Mark Uhen on 10.05.2007, edited by Kristin Feoli and Samantha Yost

Creative Commons license: CC BY (attribution)

Taxonomic list

Malacostraca
 Decapoda - Panopeidae
Panopeus herbstii9 Edwards 1834 crab
one finger, Cat. No. 166087
Chondrichthyes
 Odontaspidida - Carcharodontidae
"Oxyrhina hastalis" = Cosmopolitodus hastalis8
"Oxyrhina hastalis" = Cosmopolitodus hastalis8 Agassiz 1843 elasmobranch
 Plagiostomi - Carcharidae
Prionodon egertoni8 Agassiz 1843 elasmobranch
 Myliobatiformes - Myliobatidae
"Aetobatis arcuatus" = Aetobatis irregularis8
"Aetobatis arcuatus" = Aetobatis irregularis8 Agassiz 1843 eagle ray
 Lamniformes - Cetorhinidae
Cetorhinus sp.6 de Blainville 1816 basking shark
 Lamniformes - Lamnidae
"Oxyrhina retroflexa" = Isurus retroflexus8, Alopecias grandis n. sp.8
"Oxyrhina retroflexa" = Isurus retroflexus8 Agassiz 1843 mako shark
Alopecias grandis n. sp.8 Leriche 1942 mackerel shark
 Carchariniformes - Carcharhinidae
Galeocerdo aduncus8 Agassiz 1843 tiger shark
 Carchariniformes - Hemigaleidae
Hemipristis serra8 Agassiz 1843 ground shark
Actinopteri
 Acanthomorphata - Sciaenidae
Pogonias multidentatus n. sp.4 Cope 1869
Reptilia
 Testudines - Cheloniidae
Syllomus crispatus1 Cope 1896 sea turtle
Mammalia
 Carnivora - Phocidae
"Leptophoca lenis" = Leptophoca proxima7
"Leptophoca lenis" = Leptophoca proxima7 Van Beneden 1876 seal
 Mysticeti -
"Megaptera expansa" = Eschrichtius expansus3
"Megaptera expansa" = Eschrichtius expansus3 Cope 1868 whale
 Mysticeti - Cetotheriidae
Metopocetus durinasus n. gen. n. sp.5
Metopocetus durinasus n. gen. n. sp.5 Cope 1896 whale
locality info from Kellogg (1968)
 Mysticeti -
Eschrichtius leptocentrus n. sp.2 Cope 1867 whale
 Odontoceti - Eurhinodelphinidae
Eurhinodelphis sp., "Rhabdosteus longirostris" = Eurhinodelphis longirostris
Eurhinodelphis sp. Van Beneden and Gervais 1880 toothed whale
"Rhabdosteus longirostris" = Eurhinodelphis longirostris Du Bus 1867 toothed whale