Metaxytherium is an extinct genus of dugong that lived from the Oligocene until the end of the Pliocene. Fossil remains have been found in Africa, Europe, North America and South America. Generally marine seagrass specialists, they inhabited the warm and shallow waters of the Paratethys, Mediterranean, Caribbean Sea and Pacific coastline. American species of Metaxytherium are considered to be ancestral to the North Pacific family Hydrodamalinae, which includes the giant Steller's sea cow.
Aktiogavialis is an extinct genus of crocodylian that lived from the Oligocene until the Miocene in what is now the Caribbean. Two species have been described: Aktiogavialis puertoricensis from the Middle Oligocene of Puerto Rico and Aktiogavialis caribesi from the Huayquerian of the Late Miocene of Venezuela.
Kentriodontidae is an extinct family of odontocete whales related to modern dolphins. The Kentriodontidae lived from the Oligocene to the Pliocene before going extinct.
Siquisiquesuchus is an extinct genus of gavialid crocodilian. It is known from cranial remains and a few postcranial bones found in Miocene-age rocks of the Castillo Formation in northwestern Venezuela.
Kutchisiren is an extinct genus of mammal which existed in what is now India in Khari Nadi Formation during the Miocene period. It was named by S. Bajpai, D. P. Domning, D. P. Das, J. Velez-Juarbe, and V. P. Mishra in 2010, and the type species is Kutchisiren cylindrica. It was originally named Kotadasiren gracilis in 1994, by Das and Basu.
Meherrinia is an extinct genus of inioid river dolphin from the Meherrin River, North Carolina, in the United States. First described in 2012, the dolphin is, in most respects, intermediate in form between the living Amazon river dolphin and the La Plata dolphin, although it is probably more closely related to the former. However, the fossil was discovered in what are believed to be marine deposits, dating from the late Miocene, whereas the Amazon river dolphin is an exclusively freshwater species. Meherrinia therefore was, as of 2012, the only known marine genus of the family Iniidae, although others have been discovered since. Only one species is known.
The Parachucla Formation is a geologic formation in the southeastern United States. It preserves fossils from the Aquitanian stage of the early Miocene period. The formation is included in the Hawthorn Group. An exposure at the northern end of the formation has produced fossils estimated to be 19.4 to 20.5 Million years ago (Ma). Another exposure at the southern end of the formation has produced fossils estimated to be 23.9 to 24.7 Ma.
The Capistrano Formation is a geologic formation in coastal southern Orange County, California. It preserves fossils dating back to the late Miocene to early Pliocene, with the Oso Member representing a near-shore environment. Fifty-nine species and varieties of foraminifera are recognized from the Capistrano Formation alongside a diverse array of marine mammals including up to five species of walrus.
The Chagres Formation (Tc) is a geologic formation in the Colón Province of central Panama. The sandstones and siltstones were deposited in a shallow marine environment and preserve fossils dating back to the Middle to Late Miocene period.
The Culebra Formation (Tcb) is a geologic formation in Panama. It preserves fossils dating back to the Miocene period; Early Miocene epoch, Aquitanian to Burdigalian stages. Fossils of Culebrasuchus have been found in and named after the formation. The thickness of the formation is at least 250 metres (820 ft) thick, and the age has been estimated as from 23 to 19 Ma.
The Lares Limestone is a geologic formation in Puerto Rico. It preserves fossils dating back to the Late Oligocene to Early Miocene period.
Isthminia is a genus of medium-sized river dolphin cetaceans that lived during the Late Miocene epoch in what is now the coasts of Panama, about 6.1 million to 5.8 million years ago. The type species is I. panamensis, known from the littoral Chagres Formation.
Panamacebus is an extinct genus of monkey known from the Early Miocene of central Panama. Panamacebus transitus is the only and type species of this genus.
Scaphokogia is an extinct genus of pygmy sperm whales that lived off the coasts of Mexico and Peru, South America during the Late Miocene to Late Pliocene. Two species have currently been described: the type species S. cochlearis and S. totajpe. Fossils of Scaphokogia have been found in the Tirabuzon Formation of Baja California and the Pisco Formation of Peru. Scaphokogia existed about 5 million years ago, and were relatively rare animals.
Pteronarctos is a genus of basal pinnipediform from middle Miocene marine deposits in Oregon.
Nanokogia is an extinct genus of pygmy sperm whale that lived off the coast of Panama during the Late Miocene.
Priscosiren is an extinct genus of mammal which existed in the west Atlantic and Puerto Rico during the early Oligocene (Chattian).
Dioplotherium is an extinct genus of mammal known from Neogene deposits in the southeastern United States.
Osodobenus is an extinct genus of walrus from the Miocene to Pliocene of California. Osodobenus may have been the first tusked walrus and shows several adaptations that suggest it was a suction feeder, possibly even a benthic feeder like modern species. Three skulls are known showing pronounced sexual dimorphism, with the female lacking the same tusks as the male. Only a single species, Osodobenus eodon, is currently recognized.
Titanotaria is a genus of late, basal walrus from the Miocene of Orange County, California. Unlike much later odobenids, it lacked tusks. Titanotaria is known from an almost complete specimen which serves as the holotype for the only recognized species, Titanotaria orangensis, it is the best preserved fossil walrus currently known.
