From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Temporal range: Eocene
Machaeroides eothen.JPG
Machaeroides eothen skull
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Creodonta
Family: Oxyaenidae
Subfamily: Machaeroidinae
Genus: Machaeroides
Matthew, 1909
Type species
Machaeroides eothen
Matthew, 1909
  • M. eothen
  • M. simpsoni

Machaeroides ("dagger-like") is a genus of sabre-toothed predatory mammal that lived during the Eocene (56 to 34 mya). Its fossils were found in the U.S. state of Wyoming.



Both species bore a passing or superficial resemblance to a very small, dog-sized saber-toothed cat. Machaeroides could be distinguished from actual saber-toothed cats by their more-elongated skulls, and their plantigrade stance. Machaeroides species are distinguished from the closely related Apataelurus by the fact that the former genus had smaller saber-teeth. Despite its small size, the genus Machairoides was well-equipped to hunt prey larger than itself, such as the small, primitive horses and rhinoceroses present at the time, as it was equipped with saber teeth and powerful forelimbs to subdue prey.[1]

M. eothen weighed an estimated 10–14 kg (22–31 lb), thus matching in size a small Staffordshire Terrier. M. simpsoni was probably smaller. (Egi 2001)

Taxonomic placement[edit]

Its position within the mammals has been in dispute. Experts have been equally divided over whether Machaeroides and its sister-genus, Apataelurus, belong in Oxyaenidae or Hyaenodontidae, though the most recent studies favor the former.[2]


  1. ^ Antón, Mauricio (2013). Sabertooth. Indiana University Press. ISBN 978-0-253-01049-0.
  2. ^ Shawn, Z. (2014). "Saber-tooth origins: a new skeletal association and the affinities of Machaeroidinae (Mammalia, Creodonta)". Journal of Vertebrate Paleontology, Program and Abstracts: 259–260.
  • Egi, Naoko1 (2001). "Body Mass Estimates in Extinct Mammals from Limb Bone Dimensions: the Case of North American Hyaenodontids". Palaeontology. 44 (3): 497–528. doi:10.1111/1475-4983.00189.