The Tertiary in Maryland, US

Paleontology and geology

During the Tertiary, extensive erosion of upland areas occurred in northern Maryland as eastward-flowing streams carried large quantities of sediment to coastal areas. Sea level fluctuations continued to influence the deposition and nature of habitats in the coastal plain of eastern Maryland. The fossiliferous deposits of the Chesapeake Group along the western shore of Chesapeake Bay contain more than 600 species of molluscs, echinoderms, crabs, barnacles, brachiopods and corals. Vertebrate fossils are also common, including those of marine mammals, sharks and rays, sea birds, turtles, tortoises, and crocodiles. These fossils suggest that this area was a shallow, temperate sea during the Miocene, bordered by low sandy shores, tidal marshes, and fresh water swamps. Bones of tapirs, mastodons, rhinoceros, horses, and dogs are sometimes found in Late Tertiary (Pliocene) sediments.