| Protosirenidae Temporal range: | |
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| The skeleton of Protosiren | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Sirenia |
| Family: | † Protosirenidae Sickenberg, 1934 |
| Genera | |
Protosirenidae is an extinct primitive family of the order Sirenia. [1] [2]
Protosirenids are thought to have been amphibious quadrupeds, meaning that they spent their time both on land and in the water and had four legs. [3]
The Sirenia, commonly referred to as sea cows or sirenians, are an order of fully aquatic, herbivorous mammals that inhabit swamps, rivers, estuaries, marine wetlands, and coastal marine waters. The extant Sirenia comprise two distinct families: Dugongidae and Trichechidae with a total of four species. The Protosirenidae and Prorastomidae families are extinct. Sirenians are classified in the clade Paenungulata, alongside the elephants and the hyraxes, and evolved in the Eocene 50 million years ago (mya). The Dugongidae diverged from the Trichechidae in the late Eocene or early Oligocene.
This is a list of topics in evolutionary biology.
Hydrodamalis is a genus of extinct herbivorous sirenian marine mammals. It included the Steller's sea cow, the Cuesta sea cow, and the Takikawa sea cow. The fossil genus Dusisiren is regarded as the sister taxon of Hydrodamalis: together, the two genera form the dugong subfamily Hydrodamalinae. They were the largest member of the order Sirenia, whose only extant members are the dugong and the manatees. They reached up to 9 metres (30 ft) in length, making the Steller's sea cow among the largest mammals other than whales to have existed in the Holocene epoch. Steller's sea cow was first described by Georg Wilhelm Steller,
Prorastomus sirenoides is an extinct species of primitive sirenian that lived during the Eocene Epoch 40 million years ago in Jamaica.
Rytiodus is an extinct genus of sirenian, whose fossils have been discovered in France, Europe and Libya.
Sirenia is the order of placental mammals which comprises modern "sea cows" and their extinct relatives. They are the only extant herbivorous marine mammals and the only group of herbivorous mammals to have become completely aquatic. Sirenians are thought to have a 50-million-year-old fossil record. They attained modest diversity during the Oligocene and Miocene, but have since declined as a result of climatic cooling, oceanographic changes, and human interference. Two genera and four species are extant: Trichechus, which includes the three species of manatee that live along the Atlantic coasts and in rivers and coastlines of the Americas and western Africa, and Dugong, which is found in the Indian and Pacific oceans.
Pezosiren portelli, also known as the "walking manatee", is a basal sirenian from the early Eocene of Jamaica, 50 million years ago. The type specimen is represented by a Jamaican fossil skeleton, described in 2001 by Daryl Domning, a marine mammal paleontologist at Howard University in Washington, DC. It is believed to have had a hippopotamus-like amphibious lifestyle, and is considered a transitional form between land and sea mammals.
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.
Protosiren is an extinct early genus of the order Sirenia. Protosiren existed throughout the Lutetian to Priabonian stages of the Middle Eocene. Fossils have been found in the far-flung locations like the United States, Africa (Egypt), Europe and Asia.
Nanosiren garciae is an extinct sirenian dugong that lived in warm shallow seas in what is now Venezuela, approximately 11.610—3.6 Ma during the Miocene and Pliocene. The species is listed in the Paleobiology Database, funded by the Australian Research Council.
Prorastomidae is a family of extinct sirenians from Jamaica, related to the extant manatees and dugong. The family includes the oldest known fossils of Sirenians, represented in two genera:
Altungulata or Pantomesaxonia is an invalid clade (mirorder) of ungulate mammals comprising the perissodactyls, hyracoids, and tethytheres.
Dusisiren is an extinct genus of dugong related to the Steller's sea cow that lived in the North Pacific during the Neogene.
Prototherium is a genus of extinct sirenian related to the dugong. It is known from middle (Bartonian) and upper Eocene deposits in Italy and Spain. Type species is P. veronenses
Miosiren is an extinct genus of manatee from the Early Miocene of southeastern England (Suffolk) and Antwerp, Belgium.
Potamosiren is an extinct genus of manatee from the Middle Miocene (Laventan) Honda Group of Colombia.
The Cuesta sea cow is an extinct herbivorous marine mammal and is the direct ancestor of the Steller's sea cow. They reached up to 9 metres (30 ft) in length, making them among the biggest sirenians to have ever lived. They were first described in 1978 by Daryl Domning when fossils in California were unearthed. Its appearance and behavior are largely based on that of the well-documented Steller's sea cow, which, unlike the Cuesta sea cow, lived into the modern era and was well-described.
Lentiarenium was an early sea cow from the Late Oligocene (Chattian) Linz-Melk Formation of Austria. Known since the mid 19th century, Lentiarenium was long considered to be a species of Halitherium until a 2016 analysis showed it to be distinct.
Kaupitherium is an extinct dugongid sea cow that lived during the Oligocene. Fossils of the genus have been found in the Alzey Formation of Germany. Inside its flippers were finger bones that did not stick out. Kaupitherium also had the residues of back legs, which did not show externally. However, it did have a basic femur, joined to a reduced pelvis. Kaupitherium also had elongated ribs, presumably to increase lung capacity to provide fine control of buoyancy.
Stegosiren was an early sea cow from the Middle Oligocene of South Carolina, US. It shows a stage of halitheriine evolution more derived than that of the Old World early Oligocene Eosiren imenti and Halitherium schinzii.
{{cite book}}: |work= ignored (help) Sirenian genera | ||
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