Named By: William Diller Matthew - 1909.
Classification: Chordata, Mammalia, Creodonta.
Species: M. eothen (type), M. simpsoni.
Size: Details unavailable.
Known locations: USA.
Time period: Ypresian to early Lutetian of the Eocene.
Fossil representation: Remains of a few individuals.
of all the creodonts Machaeroides is one of the
most unique since it
possess enlarged canine teeth similar to the sabre teeth that are
commonly associated with the sabre-toothed cats of the
Pliocene/Pleistocene eras. The presence of Machaeroides
America is a clear indication that the creodonts were adapting to
fulfil various different niches. So far Machaeroides
fossils are only
known from the earlier stages of the Eocene, and disappear before the
appearance of the nimravids, another group of mammals noted for
As a predator, Machaeroides probably relied upon ambush tactics to hunt and kill prey. The landscapes of the early Eocene were covered by scrub and forest, meaning that there were endless opportunities for setting up ambush points. In addition to these landscapes, Machaeroides like other creodonts had proportionately short legs with plantigrade feet, and arrangement perfect for sudden bursts of acceleration, but features that also limited top speed. There has been some debate however over how Machaeroides was related to other creodonts with the genus usually being attributed either to Hyaenodontidae or Oxyaenidae.
Because of the ‘sabre-teeth’ and the similarity in name, caution should be used not to confuse the creodont Machaeroides with the actual sabre-toothed cat Machairodus.
The Carnivora and Insectivora of the Bridger Basin, middle Eocene. Memoirs of the AMNH ; v. 9, pt. 6, Matthew, William Diller [here]