Choptank Formation
| Choptank Formation | |
|---|---|
| Stratigraphic range: | |
Chesapecten nefrens, Choptank Formation | |
| Type | Formation |
| Unit of | Chesapeake Group |
| Underlies | St. Marys Formation |
| Overlies | Calvert Formation |
| Location | |
| Region | Virginia, Maryland |
| Country | United States |
| Type section | |
| Named for | Choptank River |
The Choptank Formation is a geologic formation in Virginia and Maryland. It preserves fossils dating from the mid-late Miocene of the Neogene period, from the latest Langhian to the early Tortonian (13.9 to 11 million years ago).[1]
Fossils
The Choptank Formation is extremely fossiliferous. Some of the fossil species represented include the following:[2][3]
Sharks
- Otodus megalodon
- Carcharodon hastalis
- Isurus oxyrhincus
- Carcharomodus escheri
- Physogaleus contortus
- Galeocerdo aduncus
- Carcharhinus
- Hemipristis serra
- Squatina sp.
- Notorhyncus cepedianus
- Carcharias
- Isurus retroflexus
- Parotodus benedeni
- Alopias vulpinus
- Alopias grandis
- Cetorhinus
- Negaprion brevirostris
- Rhizoprionodon
- Sphryna laevissima
Rays and Other Cartilaginous Fish
Fish
- Acipenseridae indet.
- Opsanus sp.
- Serranidae indet
- Pogonias sp.
- Sciaenops sp.
- Tautoga sp.
- Acanthocybium cf. solandri
- Thunnus sp.
- Istiophorus cf. platypterus
- Mola cf. pileata
- Ariopsis aff. A. felis
- Trisopterus sculptus
- Micromesistius cognatus
- Prionotus
Cetaceans
- Aglaocetus sp.
- Cetotherium sp.
- Delphinodon sp.
- Eurhinodelphis sp.
- Macrokentriodon morani
- Mesocetus
- Parietobalaena
- Orycterocetus
- Pelocetus
Pinnipeds
- Callophoca obscura
- Leptophoca proxima
- Prophoca sp.
Crocodilians
- Thecachampsa antiquus
- Thecachampsa sericodon
Invertebrates
- Chesapecten nefrens
- Chesacardium
- Euspira heros
- Mariacolpus octonnaria
- Macrocallista marylandica
- Stewartia anodonta
- Marvacrassitella marylandica
- Ecphora
- Panopea
- Albertella aberti
Terrestrial Mammals
- Cynarctus wangi
- Gomphotherium calvertensis
- Hipparion cf. phosphorum
See also
- List of fossiliferous stratigraphic units in Virginia
- Paleontology in Virginia
- Paleontology in Maryland
- Calvert Cliffs State Park
- List of fossiliferous stratigraphic units in Maryland
- Chesapeake Group
References
- ^ Carnevale, Giorgio; Godfrey, Stephen James (2018). "Miocene bony fishes from the Calvert, Choptank, St. Marys and Eastover Formations, Chesapeake Group, Maryland and Virginia". Smithsonian Contributions to Paleobiology (100).
- ^ Godfrey, Stephen J., ed. (2018-09-25). "The Geology and Vertebrate Paleontology of Calvert Cliffs, Maryland, USA". Smithsonian Contributions to Paleobiology (100): 2–274. doi:10.5479/si.1943-6688.100. ISSN 1943-6688.
- ^ "Paleobiology Collections Search". collections.nmnh.si.edu. Retrieved 2020-08-14.
- ^ "Collections". The Fossil Forum. Retrieved 2020-08-14.
- Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved 17 December 2021.