Astrapotheria

from Wikipedia, the free encyclopedia
Astrapotheria
Astrapotherium skull

Astrapotherium skull

Temporal occurrence
Upper Paleocene to Upper Miocene ( Tortonian )
58.7 to 7.25 million years
Locations
Systematics
Mammals (mammalia)
Higher mammals (Eutheria)
Laurasiatheria
Scrotifera
South American ungulates (Meridiungulata)
Astrapotheria
Scientific name
Astrapotheria
Lydekker , 1894

The Astrapotheria are a completely extinct order of herbivorous mammals from the parentage of the South American ungulates (Meridiungulata). They lived 58.7 to 7.25 million years ago, from the Upper Paleocene to the Miocene , on the South American continent . They are probably a sister group of the Xenungulata .

description

Astrapotherium

The more highly developed Astrapotheria (Astrapotheriidae) had an often large and elongated body on comparatively slender limbs. The body weight was sometimes considerable and ranged from around 320 kg to 500 kg for Comahuetherium to 4.1 t for Parastrapotherium and up to 6.4 t for Hilarcotherium . Above all the late representatives of the astrapotheria, in which giant forms are documented several times, were the largest land-living, endemic mammals of their time in South America. The neck was partially elongated and ended with a rather large and heavily built head. The structure of the skull, in particular the recessed nasal bones, suggests the presence of a short, strong trunk . On the surface, the Astrapotheria had a resemblance to contemporary tapirs without being closely related to them. The canines ( Dentes canini ) were elongated like tusks, they were followed by a wide gap (a so-called diastema ) in front of the molars (premolars and molars). The molars of the upper jaw showed a pattern on the chewing surfaces that resembled a rhinoceros . The late astrapotheria in particular had a reduced number of premolars. The function of the canines is unknown. The lower jaw bone protruded far beyond the upper jaw . It seems that the Astrapotheriidae had developed a habitus between that of today's rhinos and elephants through convergent evolution and exhibited a comparable way of life. The Pyrotheria , which also belonged to the southern ungulates, were even more similar to elephants.

Internal system

The early Eoastrastylopidae were the smallest and most primitive of the Astrapotheria. Only one type is known of them. They lived from the Paleocene to the early Eocene about 55 million years ago. The Trigonostylopidae were long regarded as a separate order. They are guaranteed until 45 million years ago. The Trigonostylops from the Paleocene, mainly known from skull finds , is viewed as a primitive form of astrapotheria. With a length of about 1.5 meters, it was significantly smaller than the Xenastrapotherium , Uruguaytherium and the 2.5 to 3 meters large Astrapotherium, which belong to the Astrapotheriidae . Especially the later, more specialized and large representatives of the Astrapotheriidae shape the image of the Astrapotheria. These are divided into two subfamilies. The Astrapotheriinae were largely limited to Patagonia , while the Uruguaytheriinae occurred further north to northern South America. Studies on the ancestral relationship showed that both form a monophyletic group. The Astrapotheria died out at the end of the Miocene around 10 million years ago.

Internal systematics of Astrapotheria according to Vallejo-Pareja et al. 2015
 Astrapotheria  

 Eoastrapostylops


  Trigonostylopidae  

 Trigonostylops


   

 Tetragonostylops


  Astrapotheriidae  

 Albertogaudrya


   

 Scaglia


   

 Astraponotus


   

 Maddenia


   

 Comahuetherium


   

 Parastrapotherium


  Astrapotheriinae  

 Astrapotherium


   

 Astrapothericulus



  Uruguaytheriinae  

 Uruguaytherium


   

 Hilarcotherium


   

 Xenastrapotherium


   

 Granastrapotherium





Template: Klade / Maintenance / 3









Template: Klade / Maintenance / Style
Granastrapotherium

The internal system according to McKenna & Bell:

  • Order Astrapotheria Lydekker , 1894
  • Family Eoastrastylopidae Soria & Powell , 1981

swell

  • Malcolm C. McKenna, Susan K. Bell: Classification of mammals above the species level. Revised edition. Columbia University Press, New York NY 2000, ISBN 0-231-11013-8 .

Individual evidence

  1. ^ A b c Alejandro Kramarz and Mariano Bond: A new early Miocene astrapotheriid (Mammalia, Astrapotheria) from Northern Patagonia, Argentina. New Yearbook for Geology and Paleontology Abhandlungen 260, 2011, pp. 277–287
  2. ↑ a b c M. C. Vallejo-Pareja, JD Carrillo, JW Moreno-Bernal, M. Pardo-Jaramillo, DF Rodriguez-Gonzalez and J. Muñoz-Duran: Hilarcotherium castanedaii, gen. Et sp. nov., a new Miocene astrapothere (Mammalia, Astrapotheriidae) from the Upper Magdalena Valley, Colombia. Journal of Vertebrate Paleontology 2015, doi : 10.1080 / 02724634.2014.903960 .
  3. ^ Juan D. Carrillo, Eli Amson, Carlos Jaramillo, Rodolfo Sánchez, Luis Quiroz, Carlos Cuartas, Aldo F. Rincón and Marcelo R. Sánchez-Villagra: The Neogene record of northern South American native ungulates. Smithsonian contributions to paleobiology 101, 2018, pp. 1–67
  4. ^ A b Alejandro Kramarz and Mariano Bond: A new Oligocene astrapothere (Mammalia, Merendungulata) from Patagonia and a new appraisal of astrapothere phylogeny. Journal of Systematic Palaeontology 7, 2009, pp. 117-128
  5. ↑ George Gaylord Simpson: The beginning of the age of mammals in South America Part II. Bulletin of the American Museum of Natural History 137, 1967, pp. 1–259 (pp. 209–235)
  6. ^ A b Steven J. Johnson and Richard H. Madden: Uruguaytheriine astrapotheres of tropical South America. In: Richard F. Kay, Richard H. Madden, Richard L. Cifelli, and John J. Flynn (Eds.): Vertebrate Paleontology in the Neotropics. The Miocene Fauna of La Venta, Colombia. Smithsonian Institution Press, Washington, 1997, pp. 355-382
  7. ↑ Malcolm C. McKenna and Susan K. Bell: Classification of mammals above the species level. Columbia University Press, New York, 1997, pp. 1-631 (pp. 466-468)
  8. ↑ Mariano Bond, Alejandro Kramarz, Ross DE MacPhee and Marcelo Reguero: A new astrapothere (Mammalia, Meridiungulata) from La Meseta Formation, Seymour (Marambio) Island, and a reassessment of previous records of Antarctic astrapotheres. American Museum Novitates 3718, 2011, pp. 1-16

Web links

Commons : Astrapotheria  - collection of images, videos and audio files