Astrapotherium ("lightning beast") is an extinct genus of large astrapotherian ungulate native to South America during the early-middle Miocene. It is the best known member of the group. The type species. A. magnus have been found in the Santa Cruz Formation in Argentina. Other fossils have been found in the Deseado, Sarmiento, and Aisol Formations of Argentina and Chile (Cura-Mallín Group).[2]

Astrapotherium
Temporal range: Early Miocene–Middle Miocene
Skull of Astrapotherium magnum
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Astrapotheria
Family: Astrapotheriidae
Subfamily: Astrapotheriinae
Genus: Astrapotherium
Burmeister, 1879
Type species
Astrapotherium magnum
Owen, 1853
Species
  • A. burmeisteri Mercerat, 1891
  • A. guillei Kramarz et al. 2019[1]
  • A. magnum Owen, 1853
  • A. ruderarium Ameghino, 1902
Synonyms
Genus synonymy
  • Listriotherium Mercerat 1891
  • Mesembriotherium Moreno 1882
  • Xylotherium Mercerat 1891
Synonyms of A. burmeisteri
  • Astrapotherium giganteum Ameghino, 1891
  • Astrapotherium delimitatum Ameghino, 1891
Synonyms of A. magnum
  • Astrapotherium columnatum Ameghino, 1891
  • Astrapotherium nanum Ameghino, 1891
  • Astrapotherium karaikense Ameghino, 1904b
  • Astrapodon carinatus Ameghino, 1891
Synonyms of A. ruderarium
  • Parastrapotherium paucum Ameghino 1902
  • Parastrapotherium crassum (partim) Ameghino 1902
  • Astrapothericulus minusculus Ameghino 1902
  • Astrapothericulus laevisculus Ameghino 1902
  • Astrapotherium triangulidens Ameghino 1902
  • Prochalicotherium patagonicum Ameghino 1902

Description edit

 
Restoration and size comparison of A. magnus

Astrapotherium had an elongated body, with a total length around 2.5 m (8.2 ft), a weight of nearly 1,000 kg (2,200 lb), and relatively short limbs.[3] Larger estimates suggest its body mass was up to 1,600–3,500 kilograms (3,500–7,700 lb).[4] It had small plantigrade feet, and the hind limbs were significantly weaker than the fore limbs. Its four canine teeth were elongated to form short tusks, and it had broad, protruding lower incisors, which likely ground against a horny pad in the upper jaw, as in many modern ruminants.[3]

 
Canine tooth of A. magnus at the Museum für Naturkunde, Berlin

Astrapotherium has been inferred to have had a tapir-like proboscis, based on its retracted narials and short upper jaw.[5]

Classification edit

Cladogram based in the phylogenetic analysis published by Vallejo-Pareja et al., 2015, showing the position of Astrapotherium:[6]

Eoastrapostylops

Paleobiology edit

The animal was probably at least partially aquatic, living in shallow water and feeding on marsh plants in a similar manner to a modern hippopotamus.[3]

References edit

  1. ^ Alejandro Kramarz; Alberto Garrido; Mariano Bond (2019). "Astrapotherium from the Middle Miocene Collón Cura Formation and the decline of astrapotheres in southern South America". Ameghiniana. in press. Archived from the original on 2017-10-02. Retrieved 2019-07-24.
  2. ^ Astrapotherium at Fossilworks.org
  3. ^ a b c Palmer, Douglas, ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 248. ISBN 1-84028-152-9.
  4. ^ Kramarz, Alejandro G.; Bond, Mariano (2008). "Revision of Parastrapotherium (Mammalia, Astrapotheria) and other Deseadan astrapotheres of Patagonia". Ameghiniana. 45 (3).
  5. ^ Milewski, Antoni V.; Dierenfeld, Ellen S. (March 2013). "Structural and functional comparison of the proboscis between tapirs and other extant and extinct vertebrates". Integrative Zoology. 8 (1): 84–94. doi:10.1111/j.1749-4877.2012.00315.x. PMID 23586563.
  6. ^ Vallejo-Pareja, M. C.; Carrillo, J. D.; Moreno-Bernal, J. W.; Pardo-Jaramillo, M.; Rodriguez-Gonzalez, D. F.; Muñoz-Duran, J. (January 2015). "Hilarcotherium castanedaii, gen. et sp. nov., a new Miocene astrapothere (Mammalia, Astrapotheriidae) from the Upper Magdalena Valley, Colombia" (PDF). Journal of Vertebrate Paleontology. 35 (2): e903960. Bibcode:2015JVPal..35E3960V. doi:10.1080/02724634.2014.903960. S2CID 130728894. Archived (PDF) from the original on 14 July 2019 – via the Colombian Geological Survey.

External links edit