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Stegosiren
Stegosiren was an early sea cow from the Middle Oligocene of South Carolina, USA. It shows a stage of halitheriine evolution more derived than that of the Old World early Oligocene '' Eosiren imenti'' and '' Halitherium schinzii''. Location Fossils of Stegosiren are known from the Middle Oligocene of South Carolina, USA. As of March 2021, the addition of ''Stegosiren macei'' to the list of potentially sympatric sirenian species lineages known from the West Atlantic-Caribbean Oligocene brings the total number of those to at least seven. Description The species is from the Ashley and Chandler Bridge Formations in South Carolina (late Rupelian–late Chattian The Chattian is, in the geologic timescale, the younger of two ages or upper of two stages of the Oligocene Epoch/Series. It spans the time between . The Chattian is preceded by the Rupelian and is followed by the Aquitanian (the lowest stage ...) and reflect a stage of halitheriine evolution more derived than t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stegosiren Skull
Stegosiren was an early sea cow from the Middle Oligocene of South Carolina, USA. It shows a stage of halitheriine evolution more derived than that of the Old World early Oligocene '' Eosiren imenti'' and '' Halitherium schinzii''. Location Fossils of Stegosiren are known from the Middle Oligocene of South Carolina, USA. As of March 2021, the addition of ''Stegosiren macei'' to the list of potentially sympatric sirenian species lineages known from the West Atlantic-Caribbean Oligocene brings the total number of those to at least seven. Description The species is from the Ashley and Chandler Bridge Formations in South Carolina (late Rupelian–late Chattian The Chattian is, in the geologic timescale, the younger of two ages or upper of two stages of the Oligocene Epoch/Series. It spans the time between . The Chattian is preceded by the Rupelian and is followed by the Aquitanian (the lowest stage ...) and reflect a stage of halitheriine evolution more derived than t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chandler Bridge Formation
The Chandler Bridge Formation is a geologic formation in South Carolina. It preserves fossils dating back to the Chattian (Late Oligocene) of the Paleogene period, corresponding to the Arikareean in the NALMA classification.Chandler Bridge Formation at .org The formation overlies the and is overlain by the Edisto Formation. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mace Brown Museum Of Natural History
The Mace Brown Museum of Natural History is a public natural history museum located on the campus of The College of Charleston, a public liberal arts college in Charleston, South Carolina. The museum has more than 30,000 vertebrate and invertebrate fossils. The collection's focus is on the paleontology of the South Carolina Lowcountry. The collection and exhibits showcase extensive fossils of late Cretaceous through Pliocene and Pleistocene marine vertebrates (sharks, rays, chimaeras, fish, marine reptiles, marine mammals) from the southeastern USA, Paleozoic and Mesozoic invertebrates and vertebrates, Mesozoic and Cenozoic fossil plants, Eocene and Oligocene land mammals from the great plains, ice age mammals, and dinosaurs. It is also a world-class collection of Oligocene cetacean fossils. The museum provides insight into the early evolution of whales and dolphins, right at the time that mysticete and odontocete whales split and echolocation evolved. The museum has the holo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rupelian
The Rupelian is, in the geologic timescale, the older of two ages or the lower of two stages of the Oligocene Epoch/Series. It spans the time between . It is preceded by the Priabonian Stage (part of the Eocene) and is followed by the Chattian Stage. Name The stage is named after the small river Rupel in Belgium, a tributary to the Scheldt. The Belgian Rupel Group derives its name from the same source. The name Rupelian was introduced in scientific literature by Belgian geologist André Hubert Dumont in 1850. The separation between the group and the stage was made in the second half of the 20th century, when stratigraphers saw the need to distinguish between lithostratigraphic and chronostratigraphic names. Stratigraphic definition The base of the Rupelian Stage (which is also the base of the Oligocene Series) is at the extinction of the foraminiferan genus ''Hantkenina''. An official GSSP for the base of the Rupelian has been assigned in 1992 (Massignano, Italy). The transitio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sympatry
In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sharing a common range exemplifies sympatric speciation. Such speciation may be a product of reproductive isolation – which prevents hybrid offspring from being viable or able to reproduce, thereby reducing gene flow – that results in genetic divergence. Sympatric speciation may, but need not, arise through secondary contact, which refers to speciation or divergence in allopatry followed by range expansions leading to an area of sympatry. Sympatric species or taxa in secondary contact may or may not interbreed. Types of populations Four main types of population pairs exist in nature. Sympatric populations (or species) contrast with parapatric populations, which contact one another in adjacent but not shared ranges and do not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene Sirenians
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The name Oligocene was coined in 1854 by the German paleontologist Heinrich Ernst Beyrich from his studies of marine beds in Belgium and Germany. The name comes from the Ancient Greek (''olígos'', "few") and (''kainós'', "new"), and refers to the sparsity of extant forms of molluscs. The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene Epoch. The Oligocene is the third and final epoch of the Paleogene Period. The Oligocene is often considered an important time of transition, a link between the archaic world of the tropical Eocene and the more modern ecosystems of the Miocene. Major changes during the Oligocene included a global expansion of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution Of Sirenians
Sirenia is the order of placental mammals which comprises modern "sea cows" (manatees and the Dugong) 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 (early Eocene-recent). 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. Origins Sirenians, along with Proboscidea (elephants), group together with the extinct Desmostylia and likely the extinct Embrithopoda to form the Tethytheria. Tethytheria is thought to have evolved f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Priscosiren
''Priscosiren'' is an extinct genus of mammal which existed in the west Atlantic and Puerto Rico during the early Oligocene (Chattian The Chattian is, in the geologic timescale, the younger of two ages or upper of two stages of the Oligocene Epoch/Series. It spans the time between . The Chattian is preceded by the Rupelian and is followed by the Aquitanian (the lowest stage ...).Jorge Vélez-Juarbe & Daryl P. Domning (2014) Fossil Sirenia of the West Atlantic and Caribbean region: X. Priscosiren atlantica, gen. et sp. nov., Journal of Vertebrate Paleontology, 34:4, 951-964, DOI: 10.1080/02724634.2013.815192 Description ''Priscosiren'' was diagnosed from other "halitheriine" dugongids by Velez-Juarbe and Domning (2014). Phylogeny ''Priscosiren'' is recovered by Velez-Juarbe and Domning (2014) as sister to the ''Metaxytherium'' + Hydrodamalinae and Dugonginae clades. References Oligocene sirenians Fossil taxa described in 2014 Prehistoric placental genera {{P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caribosiren
''Caribosiren'' is an extinct genus of mammal which existed in what is now Puerto Rico during the late Oligocene (Chattian The Chattian is, in the geologic timescale, the younger of two ages or upper of two stages of the Oligocene Epoch/Series. It spans the time between . The Chattian is preceded by the Rupelian and is followed by the Aquitanian (the lowest stage ...). References Oligocene sirenians Fossil taxa described in 1959 Prehistoric placental genera {{Paleo-sirenian-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metaxytherium
''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. Discovery and naming The first remains of ''Metaxytherium'' were described in 1822 by Anselme-Gaëtan Demarest as a species of Hippo, ''H. medius'' before the genus name ''Metaxytherium'' was coined in 1840 by De Christol. Although the type species was initially designated to be ''M. cuvieri'', later publications argued that the two species are synonymous and ''M. medium'' thus holds precedence. The grammatical changes of the species name were made to match the rules of the Internat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eosiren Imenti
''Eosiren'' is an extinct genus of sea cow that lived during the Late Eocene (later Priabonian) to Early Oligocene ( Rupelian).Zalmout I.S. & Gingerich P.D. (2012)“Late Eocene sea cows (Mammalia, Sirenia) from Wadi al Hitan in the western desert of Fayum, Egypt” ''University of Michigan Papers on Paleontology'' No. 37 Several fossils have been found in Egypt. It seems like the species ''E. abeli'' were contemporaneous with ''Protosiren'' and ''Eotheroides''. like them, ''Eosiren'' closely resembled modern sirenians. It differes from them by having somewhat larger innominates and possess thigh bone The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with t ...s. ''Eosiren'' was first described by vertebrage paleontologist Charles William Andrews in 1902, who distinguished it from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eosiren
''Eosiren'' is an extinct genus of sea cow that lived during the Late Eocene (later Priabonian) to Early Oligocene (Rupelian).Zalmout I.S. & Gingerich P.D. (2012)“Late Eocene sea cows (Mammalia, Sirenia) from Wadi al Hitan in the western desert of Fayum, Egypt” ''University of Michigan Papers on Paleontology'' No. 37 Several fossils have been found in Egypt. It seems like the species ''E. abeli'' were contemporaneous with ''Protosiren'' and ''Eotheroides''. like them, ''Eosiren'' closely resembled modern sirenians. It differes from them by having somewhat larger innominates and possess thigh bones. ''Eosiren'' was first described by vertebrage paleontologist Charles William Andrews in 1902, who distinguished it from the genus ''Halitherium'' due to differences in the teeth and mandible. Later that year, ''Science Science is a systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the universe. Science ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
