Proschismotherium
Temporal range: Early Miocene, 17.5–16.3 Ma
↓
 Santacrucian
Holotype jaw
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Pilosa
Family: †Megalonychidae
Genus: †Proschismotherium
Ameghino, 1902
Species:
†P. oppositum
Binomial name
†Proschismotherium oppositum
Ameghino, 1902

Proschismotherium is an extinct genus of ground sloth of the family Megalonychidae, endemic to Argentina during the Early Miocene. It lived from 17.5 mya — 16.3 mya, existing (as a genus) for approximately 1.2 million years.[1] The type, and only, species, P. oppositum, was named in 1902 by Florentino Ameghino based on a single specimen found in the Santacrucian-aged Colpodon Beds of Argentina.[2] Ameghino in 1902 placed Proschismotherium in the Megatheriidae,[2] alongside Hapaloides, which was its sister taxon.[1][3][4][5]

The holotype jaw was compared to that of Schismotherium fractum and was found to be roughly the same size,[2] indicating that Proschismotherium weighed roughly 45 kilograms (99 lb) and grew up to 1 metre (3.3 ft);[6] the size estimate was loosely based on Hapalops and also Schismotherium.[7]

References

  1. ^ a b R. L. Carroll. (1988). Vertebrate Paleontology and Evolution 1-698
  2. ^ a b c F. Ameghino. (1902). Première contribution à la connaissance de la fauna mammalogique des couches à Colpodon [First contribution to the knowledge of the mammalian fauna of the Colpodon Beds]. Boletin de la Academia Nacional de Ciencias de Córdoba 17:71-141
  3. ^ McKenna & Bell (1997) Classification of Mammals Above the Species Level
  4. ^ "Hapaloides". Fossilworks. Retrieved 11 August 2022.
  5. ^ "Proschismotherium". Fossilworks. Retrieved 11 August 2022.
  6. ^ Toledo, Néstor (2012-09-07). "Mass estimation of Santacrucian sloths from the Early Miocene Santa Cruz Formation of Patagonia, Argentina". Acta Palaeontologica Polonica. doi:10.4202/app.2012.0009. hdl:11336/20506.
  7. ^ Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 207. ISBN 978-1-84028-152-1.
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