Ahytherium

Source: Wikipedia, the free encyclopedia.

Ahytherium
Temporal range: Late Pleistocene (Lujanian)
Skull
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Pilosa
Family: †Megalonychidae
Genus: †Ahytherium
Cartelle et al., 2008
Species:
†A. aureum
Binomial name
†Ahytherium aureum
Cartelle et al., 2008
Poço Azul is located in Brazil
Poço Azul
Poço Azul
Poço Azul (Brazil)

Ahytherium is an extinct genus of

megalonychid sloth that lived during the Pleistocene of what is now Brazil. It contains a single species, A. aureum.[1][2]

Discovery and taxonomy

The almost-complete skeleton of Ahytherium alongside remains of another extinct sloth species,

Pontifícia Universidade Católica de Minas Gerais. The bones, which had a length of about 3 metres (9.8 ft) when put together, belong to an animal which presumably was still growing.[2]

Description

This animal is known from well-preserved and nearly complete fossils, including a skeleton of an immature specimen, which in life must have been about three meters long, one meter tall and weighing perhaps half a ton. Like all ground sloths, Ahytherium was equipped with a robust body and legs equipped with powerful claws. Ahytherium was similar to other ground sloths such as Megalonyx but possessed some features that clearly distinguished it: the head, for example, was extremely short and tall, and possessed dorsally swollen frontal bones. The zygomatic arches were wide, particularly the frontal processes, while the lacrimal bones were narrow, blade-shaped and directed anterolaterally. The dentition included canine teeth that were thin, curved and oval in cross-section. The humerus was equipped with a poorly developed deltopectoral crest, while the femur possessed a large trochanter located distally. The shape of the caudal vertebrae indicates that the tail was dorsoventrally flattened.

Classification

Ahytherium is a

Mylodontoidea.[6][7] Molecular genetic However, studies together with protein analyses failed to establish closer relationships between these individual groups.[6][7]

Much of the fossil material of Megalonychidae is fragmentary and largely incomplete. The systematic Relationships of the individual representatives of the group could be worked out therefore so far only insufficiently. However, due to the richness of forms, different lines of development can be traced. One includes largely South American representatives such as Megistonyx or Ahytherium and Ortotherium, respectively, another consists of the North American forms Megalonyx and Pliometanastes (here, since based on skeletal features, also Caribbean sloths such as Megalocnus or Neocnus).[5][8][9] Currently, however, it is not possible to determine direct ancestors for the North American representatives of Megalonychidae. Consequently, their relationship to the South American forms is rather unknown.

Below is a phylogenetic tree of the Megalonychidae, based on the work of Stinnesbeck and colleagues (2021).[10]

Megalonychidae 

Paleobiology

Ahytherium must have been a large, rather slow-moving terrestrial sloth that could defend itself from carnivores with its powerful claws. The flattened shape of the tail suggests that Ahytherium might have been a good swimmer.[2] It is suggested to have been a mixed feeder (both browsing and grazing).[11]

See also

References

  1. ^ "Ahytherium in the Paleobiology Database". Fossilworks. Retrieved 17 December 2021.
  2. ^
    doi:10.1016/j.crpv.2008.05.006
    .
  3. doi:10.1127/njgpa/233/2004/423
    .
  4. ^ a b H. Gregory McDonald; Gerardo de Iuliis (2008). "Fossil history of sloths". In Sergio F. Vizcaíno; W. J. Loughry (eds.). The Biology of the Xenarthra. University Press of Florida. pp. 39–55.
  5. ^ a b Timothy J. Gaudrin: "Phylogenetic relationships among sloths (Mammalia, Xenarthra, Tardigrada): the craniodental evidence". Zoological Journal of the Linnean Society 140, 2004, pp. 255–305.
  6. ^ a b Frédéric Delsuc, Melanie Kuch, Gillian C. Gibb, Emil Karpinski, Dirk Hackenberger, Paul Szpak, Jorge G. Martínez, Jim I. Mead, H. Gregory McDonald, Ross D.E. MacPhee, Guillaume Billet, Lionel Hautier und Hendrik N. Poinar: "Ancient mitogenomes reveal the evolutionary history and biogeography of sloths". Current Biology 29 (12), 2019, pp. 2031–2042, doi:10.1016/j.cub.2019.05.043
  7. ^ a b Samantha Presslee, Graham J. Slater, François Pujos, Analía M. Forasiepi, Roman Fischer, Kelly Molloy, Meaghan Mackie, Jesper V. Olsen, Alejandro Kramarz, Matías Taglioretti, Fernando Scaglia, Maximiliano Lezcano, José Luis Lanata, John Southon, Robert Feranec, Jonathan Bloch, Adam Hajduk, Fabiana M. Martin, Rodolfo Salas Gismondi, Marcelo Reguero, Christian de Muizon, Alex Greenwood, Brian T. Chait, Kirsty Penkman, Matthew Collins und Ross D. E. MacPhee: "Palaeoproteomics resolves sloth relationships". Nature Ecology & Evolution 3, 2019, pp. 1121–1130, doi:10.1038/s41559-019-0909-z
  8. S2CID 86159558
    .
  9. S2CID 90414512
    .
  10. S2CID 219425309
    .
  11. doi:10.1016/j.jsames.2022.103899
    .
Retrieved from "https://en.wikipedia.org/w/index.php?title=Ahytherium&oldid=1216667689"