Machaeroides

Taxobox
name = "Machaeroides"


image_caption = "M. eothen"
fossil_range = Eocene
regnum = Animalia
phylum = Chordata
classis = Mammalia
ordo = Creodonta
familia = Incertae sedis
subfamilia = Machaeroidinae
genus = "Machaeroides"
subdivision_ranks = Species
subdivision =
* "M. eothen"
* "M. simpsoni"

"Machaeroides" ("dagger-like") is a genus of sabre-toothed creodont that lived during the Eocene. Its fossils were found in the U.S. state of Wyoming. It is the earliest known sabre-toothed mammal.

Description

Either 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.

"M. eothen" weighed an estimated 10-14 kg, thus matching in size a smallish Staffordshire Terrier. "M. simpsoni" was smaller.(Egi 2001)

Taxonomic Placement

Although it is undeniably a creodont, its placement within the order is in dispute. Experts seem equally divided over whether "Machaeroides" and its sister-genus, "Apataelurus", belong in Oxyaenidae or Hyaenodontidae.

References

* (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