Hyaenodontidae

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Hyaenodontidae Fossil range: Late Paleocene to Late Miocene
Hyaenodon gigas and H. mongoliensis
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Creodonta Family: Hyaenodontidae
Genera
See text

Hyaenodontidae ("Hyena teeth") is a family of the extinct order Creodonta, which contains several dozen genera.

The Hyaenodontids were important mammalian predators that arose during the late Paleocene and persisted well into the Miocene (Barry, 1988). They were considerably more widespread and successful than the related oxyaenids. (Lambert, 163) Characterized by long skulls, slender jaws, slim bodies, and a tendency to walk on their toes rather than flat-footed (plantigrade), they ranged in size from 30 to 140 cm at the shoulder. (Lambert, 163). While Hyaenodon gigas could weigh about 500 kg^{[verification needed]}, most were in the 5-15 kg range, equivalent to a mid-sized dog (Egi, 2001). Fossil evidence of their skulls shows that they had a particularly acute sense of smell, while their teeth were adapted for shearing, rather than crushing. (Lambert, 163)

Because of their size range, it is probable that different species hunted in different ways. Smaller ones would hunt in packs during the night, and bigger, fiercer ones would hunt alone during the daylight, using their sheer size and their mighty jaws as their principal weapon. The carnassials in a hyaenodontid are the second upper and third lower molars.

Hyaenodontids ranged from North America to Africa ^[1][2], and were important hypercarnivores in Eurasia, Africa and North America during the Oligocene, but, lost ground to the carnivoran mammals, with almost the entire family becoming extinct by the close of the Oligocene. Only four genera, Megistotherium, and its sister genus, Hyainailouros, Dissopsalis, and the youngest species of Hyaenodon, H. weilini, survived into the Miocene, of which, only Dissopsalis survived long enough to go extinct at the close of the Miocene.

[edit] Genera

• ORDER CREODONTA creodonts
  • Suborder Preptotheria
    • Family Hyaenodontidae
      • Genus Arfia^{[verification needed]}
      • Genus Boualitomus
      • Genus Buhakia
      • Genus Dissopsalis
      • Genus Hyaenodon
      • Genus Laekitherium
      • Genus Limnocyon^{[verification needed]}
      • Genus Hyainailouros
      • Genus Megistotherium
      • Genus Metapterodon
      • Genus Parvagula
      • Genus Prolimnocyon^{[verification needed]}
      • Genus Prototomus^{[verification needed]}
      • Genus Pyrocyon^{[verification needed]}
      • Genus Sinopa^{[verification needed]}
      • Genus Thinocyon^{[verification needed]}
      • Genus Triacodon
      • Genus Tritemnodon^{[verification needed]}

The Machaeroidinae are sometimes placed here (e.g. by Egi, 2001)

[edit] References

• Barry, J. C. (1988): Dissopsalis, a middle and late Miocene proviverrine creodont (Mammalia) from Pakistan and Kenya. Journal of Vertebrate Paleontology 48(1): 25-45.
• Egi, Naoko (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
• Lambert, David and the Diagram Group (1985): The Field Guide to Prehistoric Life. Facts on File Publications, New York. ISBN 0-8160-1125-7