# Calvert Formation > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Calvert_Formation > Markdown URL: https://mediated.wiki/source/Calvert_Formation.md > Source: https://en.wikipedia.org/wiki/Calvert_Formation > Source revision: 1348485577 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) Geologic formation in the United States Calvert Formation Stratigraphic range: Early to Middle Miocene (Aquitanian-Langhian) Pre๊ž’ ๊ž’ O S D C P T J K Pg N Outcrops of the Calvert Formation at the Calvert Cliffs State Park Type Formation Unit of Chesapeake Group Underlies Choptank Formation Overlies Old Church Formation Location Region Maryland, Virginia, Delaware Country United States Type section Named for Calvert County The **Calvert Formation** is a [geologic formation](/source/Formation_(geology)) in [Maryland](/source/Maryland), [Virginia](/source/Virginia), and [Delaware](/source/Delaware). It preserves [fossils](/source/Fossils) dating back to the early to middle [Miocene epoch](/source/Miocene) of the [Neogene](/source/Neogene) [period](/source/Period_(geology)), between 23 and 14 million years ago.[1] It is one of the three formations which make up the [Calvert Cliffs](/source/Calvert_Cliffs_State_Park), all of which are part of the [Chesapeake Group](/source/Chesapeake_Group). ## Fossils Carcharocles megalodon partially buried in gravel along the Calvert Cliffs, Maryland Fossils from the Calvert Formation, Zone 10, Calvert Co., MD (Miocene) The Calvert Formation is extremely fossiliferous, although the most fossiliferous layers constitute a relative small section of it, dating to about 16 to 14.5 million years ago. Sediments under these layers are composed of either fine sand with few shells or (for the earliest layers) [diatomite](/source/Diatomite).[1] Some of the fossil species represented include the following:[2][3] Carcharocles megalodon partially buried in gravel along the Calvert Cliffs, Maryland ## Chondrichthyes ### Holocephalians Genus Species Family Location Stratigraphic Position Material Notes Images Edaphodon E. sp Callorhynchidae two well preserved mandibular plates Similar to E. sweeti Ischyodus I.sp Callorhynchidae many tooth fragments occasional mandibular plates Chimaera C. sp Cimaeridae ### Elasmobranchii Genus Species Location Family Stratigraphic Position Material Notes Images Notorynchus N. primigenius Hexanchidae Similar to extant N. cepedianus but differs in distribution. Hexanchus H. gigas Hexanchidae Far less common then N. primigenus Echinorhinus E. blakei Echinorhinidae Teeth and bramble thorns One of the rarest sharks in the cliffs, prefers deeper waters Squalus S. sp. 1 S. sp. 2 Squalidae Very rare Two forms of teeth, one (S.sp 2) similar to Squalus acanthias Squatina S.sp Squatinidae Teeth and Dermal thorns Rhincodon R. typus Rhincodonidae Very similar to modern R. typus A living whale shark Carcharias C. cuspidatus C. taurus C. reticulatus odontaspididae Carcharoides C. catticus Lamnidae Isurus I. oxyrinchus I. retroflexus Lamnidae Living Isurus oxyrinchus Carcharodon C. hastalis C. subserratus Lamnidae presence of C. carcharias Otodus O. chubutensis O. megalodon Otodontidae Parotodus P. benedenii incertae sedis Alopias A. cf. vulpinus A. cf. superciliosus A. grandis Alopiidae A second large species of Alopias is known from teeth with larger and coarser serrated cutting edges then A. grandis Cetorhinus C. sp Cetorhinidae Scyliorhinid. sp Scyliorhinidae Mustelus M .sp - *[Physogaleus contortus](/source/Physogaleus_contortus)* - *[Physogaleus hemmooriensis](/source/Physogaleus)* - *[Galeocerdo aduncus](/source/Galeocerdo_aduncus)* - *[Carcharhinus egertoni](/source/Carcharhinus_egertoni)* - *[Hemipristis serra](/source/Hemipristis_serra)* - *[Carcharoides catticus](https://en.wikipedia.org/w/index.php?title=Carcharoides_catticus&action=edit&redlink=1)* - *[Negaprion brevirostris](/source/Negaprion_brevirostris)* - *[Rhizoprionodon](/source/Rhizoprionodon)* - *[Sphryna laevissima](/source/Sphyrna)* ### Rays and other cartilaginous fish - *[Mobula pectinata](/source/Mobula)* - *[Mobula fragilis](/source/Mobula)* - *[Mobula loupianensis](/source/Mobula)* - *[Plinthicus stenodon](https://en.wikipedia.org/w/index.php?title=Plinthicus_stenodon&action=edit&redlink=1)* - *[Rhinoptera](/source/Rhinoptera) cf. R. studeri* - *[Aetobatus arcuatus](/source/Aetobatus)* - *[Pteromylaeus](/source/Pteromylaeus) sp.* - *[Dasyatis probsti](/source/Dasyatis)* - *[Dasyatis rugosa](/source/Dasyatis)* - *[Pristis](/source/Pristis) sp.* ### Bony fish - *[Acipenseridae](/source/Acipenseridae) indet.* - *[Bagre](/source/Bagre_(fish)) sp.* - *[Brotula](/source/Brotula_(genus)) sp.* - *[Pogonias](/source/Pogonias) sp.* - *[Sciaenops](/source/Sciaenops) sp.* - *[Tautoga](/source/Tautoga_(fish)) sp.* - *[Acanthocybium](/source/Acanthocybium) cf. solandri* - *[Thunnus](/source/Thunnus) sp.* - *[Istiophoruscf](/source/Istiophorus). platypterus* - *[Ranzania](/source/Ranzania_(fish)) grahami* - *[Ranzania](/source/Ranzania_(fish)) tenneyorum* - *[Ariopsis](/source/Ariopsis_(fish)) stauroforus* - *[Trisopterus sculptus](/source/Trisopterus)* - *[Micromesistius cognatus](/source/Micromesistius)* - *[Prionotus](/source/Prionotus)* - *[Lophius](/source/Lophius) sp.* - *[Paralbula](/source/Paralbula) dorisiae* - *[Morone](/source/Morone)* - *[Lophokatilus ereboorensis](https://en.wikipedia.org/w/index.php?title=Lophokatilus_ereboorensis&action=edit&redlink=1)* - *[Rachycentron](/source/Rachycentron) sp.* - *[Pomatomus](/source/Pomatomus) sp.* - *[Lagodon](/source/Lagodon) sp.* - *[Micropogonias](/source/Micropogonias) sp.* - *[Sphyraena](/source/Sphyraena) sp.* - *[Sarda](/source/Sarda_(fish)) sp.* - *[Makaira](/source/Makaira) cf. nigricans* - *[Chilomycterus](/source/Chilomycterus) sp.* ### Cetaceans - [Atlanticetus patulus](/source/Atlanticetus) - [Squalodon calvertensis](/source/Squalodon_calvertensis) - *[Eurhinodelphis](/source/Eurhinodelphis) sp.* - *[Parietobalaena](/source/Parietobalaena) palmeri* - *[Eobalaenoptera harrisoni](/source/Eobalaenoptera_harrisoni)* - *[Cephalotrophis coronatus](/source/Cephalotropis)* - *[Araeodelphis](/source/Araeodelphis)* - *[Cetotherium](/source/Cetotherium)* - *[Zarhachis flagellator](https://en.wikipedia.org/w/index.php?title=Zarhachis&action=edit&redlink=1)* - *[Pelocetus](/source/Pelocetus)* - *[Xiphiacetus](/source/Xiphiacetus)* ### Pinnipeds - *[Callophoca obscura](/source/Callophoca)* - *[Leptophoca](/source/Leptophoca)* ### Crocodilians - *[Thecachampsa](/source/Thecachampsa) antiquus* - *[Thecachampsa](/source/Thecachampsa) sericodon* ### Invertebrates - *[Chesapecten](/source/Chesapecten) nefrens* - *[Chesapecten](/source/Chesapecten) coccymelus* - *[Isognomon](/source/Isognomon) sp.* - *[Ecphora](/source/Ecphora)* - *[Architectonica trilineata](/source/Architectonica)* ### Terrestrial mammals - *[Cynarctus](/source/Cynarctus) marylandica* - *[Tomarctus brevirostris](/source/Tomarctus)* - *[Gomphotherium](/source/Gomphotherium) calvertensis* - *[Hipparion](/source/Hipparion) cf. phosphorum* - *[Amphicyon](/source/Amphicyon) cf. frendens* - *[Amphicyon](/source/Amphicyon) intermedius* - *[Aphelops](/source/Aphelops) sp.* - *[Archaeohippus](/source/Archaeohippus) cf. blackbergi* ### Birds - *[Mergus miscellus](/source/Mergus)* - *[Morus loxostylus](/source/Morus_(bird))* - *[Calonectris kurodai](https://en.wikipedia.org/w/index.php?title=Calonectris_kurodai&action=edit&redlink=1)* - *[Heliadornis ashbyi](/source/Heliadornis_ashbyi)* - *[Miocepphus](https://en.wikipedia.org/w/index.php?title=Miocepphus&action=edit&redlink=1)* - *[Pelagornis](/source/Pelagornis)* ## See also - [Earth sciences portal](https://en.wikipedia.org/wiki/Portal:Earth_sciences) - [Virginia portal](https://en.wikipedia.org/wiki/Portal:Virginia) - [Paleontology portal](https://en.wikipedia.org/wiki/Portal:Paleontology) - [List of fossiliferous stratigraphic units in Virginia](/source/List_of_fossiliferous_stratigraphic_units_in_Virginia) - [Paleontology in Virginia](/source/Paleontology_in_Virginia) - [Paleontology in Maryland](/source/Paleontology_in_Maryland) - [Calvert Cliffs State Park](/source/Calvert_Cliffs_State_Park) - [List of fossiliferous stratigraphic units in Maryland](/source/List_of_fossiliferous_stratigraphic_units_in_Maryland) - [Chesapeake Group](/source/Chesapeake_Group) ## References 1. ^ [***a***](#cite_ref-:0_1-0) [***b***](#cite_ref-:0_1-1) Carnevale, Giorgio; Godfrey, Stephen James (2018). ["Miocene bony fishes from the Calvert, Choptank, St. Marys and Eastover Formations, Chesapeake Group, Maryland and Virginia"](https://www.researchgate.net/publication/327907444). *Smithsonian Contributions to Paleobiology* (100). 1. **[^](#cite_ref-2)** Godfrey, Stephen J., ed. (2018-09-25). ["The Geology and Vertebrate Paleontology of Calvert Cliffs, Maryland, USA"](https://doi.org/10.5479%2Fsi.1943-6688.100). *Smithsonian Contributions to Paleobiology* (100): 2โ€“274. [doi](/source/Doi_(identifier)):[10.5479/si.1943-6688.100](https://doi.org/10.5479%2Fsi.1943-6688.100). [ISSN](/source/ISSN_(identifier)) [1943-6688](https://search.worldcat.org/issn/1943-6688). 1. **[^](#cite_ref-3)** ["Paleobiology Collections Search"](https://collections.nmnh.si.edu/search/paleo/). *collections.nmnh.si.edu*. Retrieved 2020-08-14. --- Adapted from the Wikipedia article [Calvert Formation](https://en.wikipedia.org/wiki/Calvert_Formation) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Calvert_Formation?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.