''Protosiren'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

early

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of the order

Sirenia 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 Sirenia currently comprise two distinct ...

. ''Protosiren'' existed throughout the

Lutetian The Lutetian is, in the geologic timescale, a stage or age in the Eocene. It spans the time between . The Lutetian is preceded by the Ypresian and is followed by the Bartonian. Together with the Bartonian it is sometimes referred to as the ...

Priabonian The Priabonian is, in the ICS's geologic timescale, the latest age or the upper stage of the Eocene Epoch or Series. It spans the time between . The Priabonian is preceded by the Bartonian and is followed by the Rupelian, the lowest stage ...

stages of the

Middle Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "da ...

. Fossils have been found in the far-flung locations like the United States (

South Carolina )''Animis opibusque parati'' ( for, , Latin, Prepared in mind and resources, links=no) , anthem = " Carolina";" South Carolina On My Mind" , Former = Province of South Carolina , seat = Columbia , LargestCity = Charleston , LargestMetro = ...

North Carolina North Carolina () is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. The state is the List of U.S. states and territories by area, 28th largest and List of states and territories of the United ...

and

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and ...

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

(

Egypt Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a List of transcontinental countries, transcontinental country spanning the North Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via a land bridg ...

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

(

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...

and

Hungary Hungary ( hu, Magyarország ) is a landlocked country in Central Europe. Spanning of the Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Cr ...

) and

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

(

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area, the List of countries and dependencies by population, second-most populous ...

and

Pakistan Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...

). So far, five species have been named. From comparative anatomy and chronological order,Gingerich P.D., Arif M, Bhatti M.A., Anwar M & Sanders W.J. (1997). "''Basilosaurus drazindai'' and ''Basiloterus hussaini'', New Archaeoceti (Mammalia, Cetacea) from the Middle Eocene Drazinda Formation, with a Revised Interpretation of Ages of Whale-Bearing Strata in the Kirthar Group of the Sulaiman Range, Punjab (Pakistan)". ''Contributions from the Museum of Paleontology, University of Michigan'' 30(2): p. 55–81Gingerich P.D., Muhammad A, Bhatti M.A., Raza H.A. & Raza S.M. (1995). "''Protosiren'' and ''Babiacetus'' (Mammalia, Sirenia and Cetacea) from the Middle Eocene Drazinda Formation, Sulaiman Range, Punjab (Pakistan)". ''Contributions from the Museum of Paleontology'' 29(12): p. 331–57. it has been suggested that ''P. fraasi'', ''P. sattaensis'' and ''P. smithae'' represent an ancestor-descendant lineage. ''P. eothene'' is the oldest and smallest species.Zalmout I.S., Ul-Haq M. & Gingerich P.D. (2003)
"New species of Protosiren (Mammalia, Sirenia) from the early middle Eocene of Balochistan (Pakistan)"
''Contributions from the Museum of Paleontology'' 31(3): p. 79-87

Ecology

Like the

extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extinct, ...

sirenians (

manatee Manatees (family Trichechidae, genus ''Trichechus'') are large, fully aquatic, mostly herbivorous marine mammals sometimes known as sea cows. There are three accepted living species of Trichechidae, representing three of the four living speci ...

and

dugong The dugong (; ''Dugong dugon'') is a marine mammal. It is one of four living species of the order Sirenia, which also includes three species of manatees. It is the only living representative of the once-diverse family Dugongidae; its closest m ...

), ''Protosiren'' is thought to have fed on

sea grass Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the orde ...

es as well as freshwater plants. Unlike extant sirenians, ''Protosiren'' had hind limbs. Although the limbs were well-developed, they were small and the

sacroiliac joint The sacroiliac joint or SI joint (SIJ) is the joint between the sacrum and the ilium bones of the pelvis, which are connected by strong ligaments. In humans, the sacrum supports the spine and is supported in turn by an ilium on each side. The ...

was weak. Consequently, ''Protosiren'' is thought to have been only or primarily aquatic, rarely venturing on to land.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. 37Berta, Annalisa, 2017. ''Rise of Marine Mammals: 50 Million Years of Evolution''. Johns Hopkins University Press. It has been speculated that it swam by caudal undulation and used its hind limbs to crawl along sea floors in nearshore habitats while feeding. It might have occupied a different

ecological niche In ecology, a niche is the match of a species to a specific environmental condition. Three variants of ecological niche are described by It describes how an organism or population responds to the distribution of resources and competitors (for ...

than the contemporary ''

Eotheroides ''Eotheroides'' is an extinct genus of Eocene sirenian. It is an early member of the family Dugongidae, which includes the extant dugong. Fossils have been found from Egypt, India, and Madagascar. ''Eotheroides'' was first described by Richard O ...

'', which had a closer resemblance to modern sirenians.

References

*Domning, D. P.; Morgan, G. S.; Ray, C. E. (1982). ''North American Eocene sea cows (Mammalia: Sirenia)''. Smithsonian Contributions to Paleobiology Number 52. Smithsonian Institution Press, Washington, D.C.

External links

''Protosiren''
at

The Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms. History The Paleobiology Database (PBDB) originated in the NCEAS-funded Phanerozoic Marine Pale ...

. Eocene sirenians Transitional fossils Prehistoric placental genera Taxa named by Othenio Abel Fossil taxa described in 1904 {{Paleo-sirenian-stub

Ecology

See also

References

External links