The Cuesta sea cow (Hydrodamalis cuestae) is an extinct herbivorous marine mammal and is the direct ancestor of the Steller's sea cow (Hydrodamalis gigas). 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 modern times and was well-described.
The fossils of the Cuesta sea cow were first discovered in the Late Pliocene sediment formations of Pismo Beach, California in 1978, and successive finds of the species were unearthed elsewhere in California.[2] In 1988, fossils of sea cows were discovered in Hokkaido that were originally assigned to the Takikawa sea cow (H. spissa),[3] a newly described species, but this is thought of by some scientists as a synonym of H. cuestae. It is uncertain whether or not H. spissa was simply a local variant of H. cuestae or a completely separate lineage.[3] The Steller's sea cow was apparently a direct descendant of the Cuesta sea cow.[4]
The Cuesta sea cow went extinct around 2½ million years ago. The disappearance of the Cuesta sea cow was likely linked to the onset of the Quaternary glaciation. Its main food source of seagrasses declined, due to the cooling of the oceans, to a point where it could no longer support the population. In addition, this sea cow was not adapted to the cold, and those that were probably gave rise to the Steller's sea cow.[2]
Biology and behavioredit
The Cuesta sea cow, like the Steller's sea cow, was probably gregarious and lived in small family groups. The bones were dense and served as a sort of ballast to prevent floating, probably so that they could feed on bottom-dwelling sea grasses. Sea grasses were their preferred food source. They most likely 'walked' along the shallow seafloor using their front limbs, using their powerful tail fin for propulsion. It has been speculated that, like the Steller's sea cows, the front limbs were used as holdfasts. The Cuesta sea cow was among the largest of the sirenians to have ever lived, reaching up to 9 metres (30 ft) in length and possibly 10 tonnes (11 short tons). The body was fusiform, tapered at both the head and tail.[2][5]
^Furusawa, Hitoshi (2004). "A phylogeny of the North Pacific Sirenia (Dugongidae: Hydrodamalinae) based on a comparative study of endocranial casts". Paleontological Research. 8 (2): 91–98. doi:10.2517/prpsj.8.91.
^ abcDomning, Daryl P. (1978). "An Ecological Model for Late Tertiary Sirenian Evolution in the North Pacific Ocean". Systematic Zoology. 25 (4): 352–362. doi:10.2307/2412510. JSTOR 2412510.
^ abFurusawa, H. (1988). A new species of hydrodamaline Sirenia from Hokkaido, Japan. Takikawa Museum of Art and Natural History. pp. 1–73.
^Marsh, Helene; O'Shea, Thomas J.; Reynolds III, John E. (2011). "Steller's sea cow: discovery, biology and exploitation of a relict giant sirenian". Ecology and Conservation of the Sirenia: Dugongs and Manatees. New York: Cambridge University Press. pp. 18–35. ISBN978-0-521-88828-8.
^"Hydrodamalis cuestae" (in Russian). Age of Mammals. 2013. Archived from the original on 17 April 2013. Retrieved 2 September 2016.
December 07, 2023
cuesta, hydrodamalis, cuestae, extinct, herbivorous, marine, mammal, direct, ancestor, steller, hydrodamalis, gigas, they, reached, metres, length, making, them, among, biggest, sirenians, have, ever, lived, they, were, first, described, 1978, daryl, domning, . The Cuesta sea cow Hydrodamalis cuestae is an extinct herbivorous marine mammal and is the direct ancestor of the Steller s sea cow Hydrodamalis gigas 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 modern times and was well described Cuesta sea cowTemporal range Late Pliocene to early Quaternary 3 6 2 6 Ma PreꞒ Ꞓ O S D C P T J K Pg N Skull of Hydrodamalis cuestae at San Diego Natural History MuseumScientific classificationDomain EukaryotaKingdom AnimaliaPhylum ChordataClass MammaliaOrder SireniaFamily DugongidaeGenus HydrodamalisSpecies H cuestaeBinomial name Hydrodamalis cuestaeDomning 1978Synonyms H spissa Furusawa 1988 Contents 1 Taxonomy and extinction 2 Biology and behavior 3 See also 4 ReferencesTaxonomy and extinction editRelations within HydrodamalinaeSirenia Dusisiren reinharti Dusisiren jordani Dusisiren dewana Dusisiren takasatensis Hydrodamalis cuestae Hydrodamalis spissa Hydrodamalis gigasBased on a 2004 study by Hitoshi Furusawa 1 The fossils of the Cuesta sea cow were first discovered in the Late Pliocene sediment formations of Pismo Beach California in 1978 and successive finds of the species were unearthed elsewhere in California 2 In 1988 fossils of sea cows were discovered in Hokkaido that were originally assigned to the Takikawa sea cow H spissa 3 a newly described species but this is thought of by some scientists as a synonym of H cuestae It is uncertain whether or not H spissa was simply a local variant of H cuestae or a completely separate lineage 3 The Steller s sea cow was apparently a direct descendant of the Cuesta sea cow 4 The Cuesta sea cow went extinct around 2 million years ago The disappearance of the Cuesta sea cow was likely linked to the onset of the Quaternary glaciation Its main food source of seagrasses declined due to the cooling of the oceans to a point where it could no longer support the population In addition this sea cow was not adapted to the cold and those that were probably gave rise to the Steller s sea cow 2 Biology and behavior editThe Cuesta sea cow like the Steller s sea cow was probably gregarious and lived in small family groups The bones were dense and served as a sort of ballast to prevent floating probably so that they could feed on bottom dwelling sea grasses Sea grasses were their preferred food source They most likely walked along the shallow seafloor using their front limbs using their powerful tail fin for propulsion It has been speculated that like the Steller s sea cows the front limbs were used as holdfasts The Cuesta sea cow was among the largest of the sirenians to have ever lived reaching up to 9 metres 30 ft in length and possibly 10 tonnes 11 short tons The body was fusiform tapered at both the head and tail 2 5 See also editSteller s sea cow Takikawa sea cow HydrodamalinaeReferences edit Furusawa Hitoshi 2004 A phylogeny of the North Pacific Sirenia Dugongidae Hydrodamalinae based on a comparative study of endocranial casts Paleontological Research 8 2 91 98 doi 10 2517 prpsj 8 91 a b c Domning Daryl P 1978 An Ecological Model for Late Tertiary Sirenian Evolution in the North Pacific Ocean Systematic Zoology 25 4 352 362 doi 10 2307 2412510 JSTOR 2412510 a b Furusawa H 1988 A new species of hydrodamaline Sirenia from Hokkaido Japan Takikawa Museum of Art and Natural History pp 1 73 Marsh Helene O Shea Thomas J Reynolds III John E 2011 Steller s sea cow discovery biology and exploitation of a relict giant sirenian Ecology and Conservation of the Sirenia Dugongs and Manatees New York Cambridge University Press pp 18 35 ISBN 978 0 521 88828 8 Hydrodamalis cuestae in Russian Age of Mammals 2013 Archived from the original on 17 April 2013 Retrieved 2 September 2016 Retrieved from https en wikipedia org w index php title Cuesta sea cow amp oldid 1118032040, wikipedia, wiki, book, books, library,
