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

Where: Westmoreland County, Virginia (38.2° N, 76.8° W: paleocoordinates 38.4° N, 74.0° W)

• coordinate estimated from map

When: Calvert Beach Member (Calvert Formation), Serravallian (13.8 - 11.6 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).

•Zones 14-16A are regarded as Serravallian in age.

• 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 herbstii10 Edwards 1834 crab
one finger, Cat. No. 166087
Reptilia
 Testudines - Cheloniidae
Syllomus crispatus1 Cope 1896 sea turtle
Mammalia
 Carnivora - Phocidae
"Leptophoca lenis" = Leptophoca proxima8
"Leptophoca lenis" = Leptophoca proxima8 Van Beneden 1876 seal
 Cetacea -
Westmorelandelphis tacheroni n. gen. n. sp.6 Godfrey and Lambert 2023 toothed whale
holotype USNM PAL 317882
 Cetacea - 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
 Cetacea -
Eschrichtius leptocentrus n. sp.2, "Megaptera expansa" = Eschrichtius expansus3
Eschrichtius leptocentrus n. sp.2 Cope 1867 whale
"Megaptera expansa" = Eschrichtius expansus3 Cope 1868 whale
 Cetacea - Cetotheriidae
Metopocetus durinasus n. gen. n. sp.5
Metopocetus durinasus n. gen. n. sp.5 Cope 1896 whale
locality info from Kellogg (1968)
Actinopteri
 Acanthuriformes - Sciaenidae
Pogonias multidentatus n. sp.4 Cope 1869
Chondrichthyes
 Carcharhiniformes - Hemigaleidae
Hemipristis serra9 Agassiz 1835 ground shark
 Carcharhiniformes - Galeocerdidae
Galeocerdo aduncus9 Agassiz 1835 tiger shark
 Carcharhiniformes - Carcharhinidae
Prionodon egertoni9 Agassiz 1843 blue shark
 Lamniformes - Lamnidae
"Oxyrhina retroflexa" = Isurus retroflexus9, "Oxyrhina hastalis" = Carcharodon hastalis9
"Oxyrhina retroflexa" = Isurus retroflexus9 Agassiz 1838 mackerel shark
"Oxyrhina hastalis" = Carcharodon hastalis9 Agassiz 1838 white shark
 Lamniformes - Alopiidae
"Alopecias grandis n. sp." = Alopias grandis9
"Alopecias grandis n. sp." = Alopias grandis9 Leriche 1942 thresher shark
 Lamniformes - Cetorhinidae
Cetorhinus sp.7 de Blainville 1816 basking shark
 Myliobatiformes - Aetobatidae
"Aetobatis arcuatus" = Aetobatus irregularis9
"Aetobatis arcuatus" = Aetobatus irregularis9 Agassiz 1843 stingray