78SK57 - Unit 4 (lower half) (Miocene of the United States)

Also known as B-546

Where: Calvert County, Maryland (38.4° N, 76.5° W: paleocoordinates 38.6° N, 73.6° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Drumcliff Member (Choptank Formation), Serravallian (13.8 - 11.6 Ma)

• STRATIGRAPHIC RELATIONS: From Drumcliff Mbr of the Choptank Fm, Chesapeake Grp. AGE: Middle Miocene. STRATIGRAPHIC POSITION: From lower half of unit 4.

• bed-level stratigraphic resolution

Environment/lithology: coastal; unlithified, fine-grained, medium, shelly/skeletal sandstone

• ENVIRONMENT: Shallow marine siliciclastic.
• SPECIFIC LITHOLOGY: Hashy, shell-supported fine-medium sand. LITHIFICATION: Unlithified, based on visual inspection of collection by enterer.

Size class: macrofossils

Collected by Kidwell in 1978; reposited in the YPM

Collection methods: bulk, sieve,

• COLLECTOR: S.K. Kidwell, 1978. REPOSITORY: Peabody Museum of Natural History, Yale University.

Primary reference: S. M. Kidwell. 1982. Stratigraphy, invertebrate taphonomy and depositional history of the Miocene Calvert and Choptank Formations, Atlantic Coastal Plain. Unpublished PhD thesis, Yale University 1-511 [A. Hendy/A. Hendy/A. Hendy]more details

Purpose of describing collection: taphonomic analysis

PaleoDB collection 79109: authorized by Austin Hendy, entered by Austin Hendy on 25.02.2008

Creative Commons license: CC BY (attribution)

Taxonomic list

• COVERAGE: Exhaustive for gastropoda, bivalvia, and scaphopoda. NOMENCLATURE: Somewhat modern. Identifications are based on Martin (1904) for gastropods and bivalves, with revisions following subsequent publications.
Thecostraca
 Balanomorpha - Balanidae
Bivalvia
 Nuculanida - Yoldiidae
Yoldia sp. Möller 1842 clam
 Nuculida - Nuculidae
Nucula ? taphria Dall 1898 nut clam
 Lucinida - Lucinidae
"Megaxinus anodonta" = Stewartia anodonta, "Parvilucina crenulatus" = Parvilucina crenulata
"Megaxinus anodonta" = Stewartia anodonta Say 1824 clam
"Parvilucina crenulatus" = Parvilucina crenulata Conrad 1840 clam
 Pholadida - Corbulidae
"Caryocorbula inaequalis" = Corbula inaequalis, Bicorbula idonea
"Caryocorbula inaequalis" = Corbula inaequalis Say 1824 clam
Bicorbula idonea Conrad 1833 clam
 Cardiida - Glossidae
Glossus sp. Poli 1795 clam
 Cardiida - Mactridae
Spisula subparilis Conrad 1841 clam
 Cardiida - Veneridae
Veneridae indet. Rafinesque 1815 venus clam
? Pitar subnasuta venus clam
Dosinia acetabulum Conrad 1832 venus clam
Mercenaria sp. Schumacher 1817 quahog
 Cardiida - Cardiidae
"Cerastoderma laqueatum" = Chesacardium laqueatum
"Cerastoderma laqueatum" = Chesacardium laqueatum Conrad 1830 cockle
 Cardiida - Semelidae
Semele ? carinata Conrad 1830 clam
 Carditida - Astartidae
Astarte thisphila Glenn 1904 clam
 Carditida - Carditidae
Cyclocardia granulata Say 1824 clam
 Carditida - Crassatellidae
"Eucrassatella turgidulus" = Marvacrassatella turgidula
"Eucrassatella turgidulus" = Marvacrassatella turgidula Conrad 1843 clam
 Mytilida - Mytilidae
Modiolus sp. Lamarck 1801 mussel
 Pectinida - Pectinoidae
"Chesapecten nefrens" = Chesapecten (Chesapecten) nefrens
"Chesapecten nefrens" = Chesapecten (Chesapecten) nefrens Ward and Blackwlder 1975 scallop
 Arcida - Arcidae
"Anadara staminea" = Dallarca staminea
"Anadara staminea" = Dallarca staminea Say 1832 clam
Gastropoda
 Trochoidea - Trochidae
Calliostoma sp. Swainson 1840 top snail
? Calliostoma sp. Swainson 1840 top snail
 Neogastropoda - Muricidae
Ecphora sp. Conrad 1843 murex snail
 Sorbeoconcha - Naticidae
"Lunatia heros" = Euspira heros
"Lunatia heros" = Euspira heros Say 1822 moon snail
 Cerithioidea - Turritellidae
"Turritella plebeia" = Mariacolpus plebeia
"Turritella plebeia" = Mariacolpus plebeia Say 1824 turret shell
 Neotaenioglossa - Calyptraeidae
Crucibulum sp. Schumacher 1817 slipper shell
 Epitonioidea - Epitoniidae
"Scala sp." = Epitonium (Scala)
"Scala sp." = Epitonium (Scala) Humphrey wentletrap