Calvert Formation

The Calvert Formation is a geologic formation in Maryland, Virginia, and Delaware. It preserves fossils dating back to the early to middle Miocene epoch of the Neogene period, between 23 and 14 million years ago. It is one of the three formations which make up the Calvert Cliffs, all of which are part of the Chesapeake Group.

Fossils

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. == Chondrichthyes ==

Chondrichthyes

Holocephalians Elasmobranchii • • Physogaleus contortus • Physogaleus hemmooriensis • Galeocerdo aduncus • Carcharhinus egertoni • Hemipristis serra • Carcharoides catticus • Negaprion brevirostris • Rhizoprionodon • Sphryna laevissima • Rays and other cartilaginous fish • Mobula pectinata • Mobula fragilis • Mobula loupianensis • Plinthicus stenodon • Rhinoptera cf. R. studeri • Aetobatus arcuatus • Pteromylaeus sp. • Dasyatis probsti • Dasyatis rugosa • Pristis sp. Bony fish • Acipenseridae indet. • Bagre sp. • Brotula sp. • Pogonias sp. • Sciaenops sp. • Tautoga sp. • Acanthocybium cf. solandri • Thunnus sp. • Istiophoruscf. platypterus • Ranzania grahami • Ranzania tenneyorum • Ariopsis stauroforus • Trisopterus sculptus • Micromesistius cognatus • Prionotus • Lophius sp. • Paralbula dorisiae • Morone • Lophokatilus ereboorensis • Rachycentron sp. • Pomatomus sp. • Lagodon sp. • Micropogonias sp. • Sphyraena sp. • Sarda sp. • Makaira cf. nigricans • Chilomycterus sp. Cetaceans • Atlanticetus patulus • Squalodon calvertensis • Eurhinodelphis sp. • Parietobalaena palmeri • Eobalaenoptera harrisoni • Cephalotrophis coronatus • Araeodelphis • Cetotherium • Zarhachis flagellator • Pelocetus • Xiphiacetus Pinnipeds • Callophoca obscura • Leptophoca Crocodilians • Thecachampsa antiquus • Thecachampsa sericodon Invertebrates • Chesapecten nefrens • Chesapecten coccymelus • Isognomon sp. • Ecphora • Architectonica trilineata Terrestrial mammals • Cynarctus marylandica • Tomarctus brevirostris • Gomphotherium calvertensis • Hipparion cf. phosphorum • Amphicyon cf. frendens • Amphicyon intermedius • Aphelops sp. • Archaeohippus cf. blackbergi Birds • Mergus miscellus • Morus loxostylus • Calonectris kurodai • Heliadornis ashbyi • Miocepphus • Pelagornis == See also ==

Source: Wikipedia ↗

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