Machairodus

Machairodus Temporal range: Middle Miocene–Pleistocene PreЄ Є O S D C P T J K Pg N
Machairodus giganteus skull
Conservation status
Fossil
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora
Family:	Felidae
Subfamily:	†Machairodontinae
Tribe:	†Machairodontini
Genus:	†Machairodus Kaup, 1833
Species
†Machairodus africanus †Machairodus aphanistus †Machairodus giganteus †Machairodus oradensis †Machairodus colorandensis †Machairodus transvaalensis †Machairodus alberdiae †Machairodus copei †Machairodus laskarevi †Machairodus irtyschensis †Machairodus kabir †Machairodus kurteni †Machairodus fires †Machairodus ischimicus †Machairodus schlosseri †Machairodus palanderi †Machairodus palmidens †Machairodus inexpectatus †Machairodus giganteus †(Amphimachairodus giganteus)

Machairodus was a genus of large machairodontine saber-toothed cats that lived in Europe, Asia, Africa and North America during the Miocene through Pleistocene living from 11.6mya—126,000 years ago, existing for approximately 11.5 million years.^[1]

Species

A Machairodus palanderi skull with chipped left canine and more severely damaged right canine. This chipping is not severe enough to be called a true break, which would be in excess of half of the canine

The fossil species assigned to the genus Machairodus were divided by Turner into two grades of evolutionary development - M. aphanistus and the North American "Nimravides" catacopis representing the more primitive grade, and M. coloradensis and M. giganteus representing the more derived grade.^[2] The characteristics of the more advanced grade include a relative elongation of the forearm and a shortening of the lumbar region of the spine to resemble that in living pantherine cats.^[2] These trends would be taken further in Homotherium, which is thought to have evolved from Machairodus.

Anatomy

A very early restoration by Lancelot Speed from 1905 depicting Machairodus as essentially a snarling tiger with very long canines

"Nimravides" catacopis stood about 1 m at the shoulder. Machairodus coloradensis was apparently significantly larger, about 1.2 m at the shoulder, according to skeletal and life reconstructions.^[2] If accurate, this would make M. coloradensis one of the largest felids.

The skull of Machairodus was noticeably narrow compared with the skulls of modern pantherine big cats, and the orbits were relatively small. The canines were long, thin and flattened from side to side but broad from front to back like the blade of a knife, as in Homotherium. The front and back edges of the canines were serrated when they first grew, but these serrations were worn down in the first few years of the animal's life.

There was marked sexual dimorphism in Machairodus giganteus, with males much larger than females.^[2]

A single fossil specimen examined by Legendre and Roth was determined to have an approximate body mass of 201.8 kg.

Machairodus kabir was a large species from Central Africa whose size may have approached 500kg with a range of 350-470kg.

Machairodus was about 2M long and probably hunted as an ambush predator. Its legs were too short to sustain a long chase, so it most likely was a good jumper, and used its canines to cut open the throat of its prey. Its teeth were rooted to its mouth and were not too delicate, unlike most saber-toothed cats of the time, which had extremely long canines which hung out of their mouths. The machairodus' fangs, however, were able to more easily fit in its mouth comfortably while being long and effective for hunting.

^[3]

References