Miomachairodus is an extinct genus of large saber-toothed cats of the subfamily Machairodontinae. It is known from Miocene-age fossils in China and Turkey and persisted until the Late Miocene (early Vallesian). Miomachairodus may have coexisted with the barbourofelid Barbourofelis in its North American range.
Fossil record[]
Fossils have been found in the Vallesian-age Bahe Formation in Shaanxi, China, and Yeni Eskihisar in Anatolia. This Turkish site is of Miocene age and is well known for its pollen studies.
Morphology[]
Miomachairodus was generally small, and the canines already began to show the flattening that would soon advance into the distinct "saber-tooth" design of the more advanced machairodonts. Miomachairodus was not the ancestor to all machairodonts; this title most likely rested with Pseudaelurus. This genus is thought to be ancestral to both machairodontinae and felini, the clades of saber-toothed and conical-toothed (modern) felids.
Comparison to Relatives[]
A sister taxon of Miomachairodus is the more well known Machairodus. Of the several species of widespread Machairodus, M. giganteus is probably the most well known. The fossil record is well established in its wide range of Eurasia. Pseudaelurus ogygia stood at 58 cm at the shoulder, and its ancestor Miomachairodus advances little in size, but between Miomachairodus and its descendants of the tribe Homotherini (one of three machairodont tribes; including Machairodus and Homotherium), they grow to massive sizes, surpassing the modern lion. Most Machairodus species reach 120 cm shoulder height, and Homotherium reaches 110 cm, when compared to the 95 cm shoulder height of the modern Bengal tiger. Machairodus rivals in size among the cats only Smilodon populator of South American Pleistocene.
The Machairodus was a massive creature with a tail of medium length that did not reach the ground while standing, large ribcage, stout body, and especially strong forequarters. Its skull was long, canines of moderate length for a machairodont, making it a very good representative of the group. Sexual dimorphism displayed itself in males that were much larger and, unusual for carnivores, the main killing apparatus, the canines, were shaped differently and were surely not capable of exactly the same method of killing. Male canines were shorter and much more stout, while females were long and thin. The question of the specific usage of the canines is still in limbo, and Machairodus offers a good deal of suggestion as to how they were used, giving support to the usually inadequate claim that they were used for show, not for killing, though the hypothesis is still generally discarded. Machairodus was also in the leagues of the extreme carnivores, or hypercarnivores who could consume little but meat, and generally fresh meat at that, so scavenging was usually out of the range of means of sustenance. It has been thought that Machairodus hunted in groups, along with Homotherium, who are strangely linked to juvenile Mammoth remains.