Chasmaporthetes


Chasmaporthetes, also known as hunting or running hyena, is an extinct genus of hyenas distributed in Eurasia, North America, and Africa during the Pliocene-Pleistocene epochs, living from 4.9 million to 780,000 years ago, existing for about. The genus probably arose from Eurasian Miocene hyenas such as Thalassictis or Lycyaena, with C. borissiaki being the oldest known representative. The species C. ossifragus was the only hyena to cross the Bering land bridge into the Americas, and ranged over what is now Arizona and Mexico during Blancan and early Irvingtonian Land Mammal ages, between 5.0 and 1.5 million years ago.
Chasmaporthetes was one of the so-called "dog-like" hyenas, a hyaenid group which, in contrast to the now more common "bone-crushing" hyenas, evolved into slender-limbed, cursorial hunters like modern canids.

Taxonomy and etymology

Chasmaporthetes was named by Hay, who noted that the name meant that the North American species, Chasmaporthetes ossifragus possibly saw the beginning of the Grand Canyon.

Species

At least nine species are currently recognised:
  • Chasmaporthetes ossifragus Hay, 1921 - North America, Pliocene to Pleistocene
  • C. australis Hendey, 1974 - Africa, Late Miocene
  • C. bonisi Koufos, 1987 - Greece, Late Miocene
  • C. borissiaki Khomenko, 1932 - Russia, Pliocene
  • C. exitelus Kurtén & Werdelin, 1988 - China, Late Miocene
  • C. gangsriensis Tseng, Li, & Wang, 2013 - Asia, Early Pliocene
  • C. lunensis Del Campana, 1914 - Eurasia, Late Miocene to Early Pleistocene
  • C. melei Rook et al, 2004 - Sardinia, Early Pleistocene
  • C. nitidula Geraads, 1997 - Africa, Pliocene to Early Pleistocene

    Anatomy and paleoecology

The limb bones of Chasmaporthetes were long and slender like those of cheetahs. It likely inhabited open ground and was a daytime hunter. In Europe, the species C. lunensis competed with the giant cheetah Acinonyx pardinensis, and may have preyed on the small Bourbon gazelle and the chamois antelope. The North American C. ossifragus was similar in build to C. lunensis, but had slightly more robust jaws and teeth. It may have preyed on the giant marmot Paenemarmota, and competed with the far more numerous Borophagus diversidens.
The cheek teeth of Chasmaporthetes were slender and sharp-edged like those of felids. A study on the genus' premolar intercuspid notches indicated Chasmaporthetes was likely hypercarnivorous rather than durophagous as its modern cousins are. The microstructure of the enamel of C. lunensis lunensis consists of more gently folding enamel than that found in bone-crushing hyaenids, further supporting the notion that it was not a specialist osteophage. Dental microwear of C. australis from Langebaanweg in South Africa shows that the species was hypercarnivorous and rarely engaged in durophagy; its dental microwear was similar to the modern lion, which seldom consumes bone.