Borophagus orc
Encyclopedia
Borophagus orc is an extinct species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Borophagus
Borophagus
Borophagus is an extinct genus of the subfamily Borophaginae, a group of canids endemic to North America from the early Miocene epoch through the Zanclean stage of the Pliocene epoch 23.3—3.6 Mya. Borophagus existed for approximately .-Overview:Borophagus, like other borophagines, are loosely...

 of the subfamily Borophaginae
Borophaginae
The subfamily Borophaginae is an extinct group of canids called "bone crushing dogs" that were endemic to North America during the Oligocene to Pliocene and lived roughly 36—2.5 million years ago and existing for approximately .-Origin:...

, a group of canids endemic to North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 from the late Zanclean
Zanclean
The Zanclean is the lowest stage or earliest age on the geologic time scale of the Pliocene. It spans the time between 5.332 and 3.6 Ma ± 0.005 Ma . It is preceded by the Messinian age of the Miocene epoch, and followed by the Piacenzian age....

 stage of the Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...

 epoch (10.3 Mya) through the Hemphillian
Hemphillian
The Hemphillian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology , typically set from 10,300,000 to 4,900,000 years BP, a period of . It is usually considered to overlap the Tortonian epoch of the Late...

 stage of the Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...

 epoch (4.9 Mya). Borophagus orc existed for approximately .

Overview

Borophagus, like other Borophaginae, are loosely known as "bone-crushing" or "hyena
Hyena
Hyenas or Hyaenas are the animals of the family Hyaenidae of suborder feliforms of the Carnivora. It is the fourth smallest biological family in the Carnivora , and one of the smallest in the mammalia...

-like" dogs. Though not the most massive borophagine by size or weight, it had a more highly-evolved capacity to crunch bone than earlier, larger genera such as Epicyon
Epicyon
Epicyon is a large extinct canid genus of the subfamily Borophaginae , native to North America. It lived from the Hemingfordian age of the Early Miocene to the Hemphillian of the Late Miocene Epicyon ("near dog") is a large extinct canid genus of the subfamily Borophaginae ("bone-crushing dogs"),...

, which seems to be an evolutionary trend of the group (Turner, 2004). During the Pliocene epoch, Borophagus began being displaced by Canis genera such as Canis edwardii
Canis edwardii
Canis edwardii is an extinct species of Canidae which was endemic to most of North America from the Blancan stage of the Pliocene epoch through to the Irvingtonian stage of the Pleistocene epoch, living 4.9 Mya—300,000 years ago, existing for approximately...

 and later by Canis dirus. Early species of Borophagus were placed in the genus Osteoborus until recently, but the genera
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 are now considered synonyms. Borophagus orc possibly led a hyena-like lifestyle scavenging carcasses of recently dead animals.

Taxonomy

Typical features of this genus are a bulging forehead and powerful jaws; it was probably a scavenger
Scavenger
Scavenging is both a carnivorous and herbivorous feeding behavior in which individual scavengers search out dead animal and dead plant biomass on which to feed. The eating of carrion from the same species is referred to as cannibalism. Scavengers play an important role in the ecosystem by...

. Its crushing premolar
Premolar
The premolar teeth or bicuspids are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant, making eight premolars total in the mouth. They have at least two cusps. Premolars can be considered as a 'transitional tooth' during chewing, or...

 teeth and strong jaw muscles would have been used to crack open bone, much like the hyena of the Old World. The adult animal is estimated to have been about 80 cm in length, similar to a coyote
Coyote
The coyote , also known as the American jackal or the prairie wolf, is a species of canine found throughout North and Central America, ranging from Panama in the south, north through Mexico, the United States and Canada...

, although it was much more powerfully built.

Morphology

Two fossil specimens of Borophagus orc were measured by Legendre and Roth in 1988. They estimated that specimen one weighed 24.3 kg (53.5 lbs) and the second weighed 22 kg (48.5 lbs).

Fossil distribution

Specimens were found at only 2 sites. Near Withlacoochee River
Withlacoochee River
Withlacoochee River may refer to:* Withlacoochee River , aka Withlacoochee River , which originates in Georgia but ends in Florida* Withlacoochee River , aka Withlacoochee River , which flows entirely through Florida...

, Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...

 and coastal North Carolina
North Carolina
North Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...

.

Species

  • Borophagus diversidens
    Borophagus diversidens
    Borophagus diversidens is an extinct species of the genus Borophagus of the subfamily Borophaginae, a group of canids endemic to North America from the early Miocene epoch through the Pliocene epoch 4.9—1.8 Ma. Borophagus dudleyi existed for approximately .-Overview:Borophagus diversidens was...

     existed for (synonymous with Felis hillianus, Hyaenognathus matthewi, Hyaenognathus pachyodon, Hyaenognathus solus, Porthocyon dubius)
  • Borophagus dudleyi
    Borophagus dudleyi
    Borophagus dudleyi is an extinct species of the genus Borophagus of the subfamily Borophaginae, a group of canids endemic to North America from the late Hemphillian of the Miocene epoch through the Pliocene epoch...

     existed for
  • Borophagus hilli
    Borophagus hilli
    Borophagus hilli is an extinct species of the genus Borophagus of the subfamily Borophaginae, a group of canids endemic to North America from the early Miocene epoch through the Pliocene epoch . Borophagus dudleyi existed for approximately .-Overview:Borophagus hilli was named by C. S. Johnston...

     existed for (synonymous with Osteoborus crassapineatus, Osteoborus progressus)
  • Borophagus littoralis
    Borophagus littoralis
    Borophagus littoralis is an extinct species of the genus Borophagus of the subfamily Borophaginae, a group of canids endemic to North America from the early Miocene epoch through the Pliocene epoch...

     existed for (syn. Osteoborus diabloensis)
  • Borophagus parvus
    Borophagus parvus
    Borophagus parvus is an extinct species of the genus Borophagus, of the subfamily Borophaginae, a group of canids endemic to North America from the late Hemphillian of the Miocene epoch through the Pliocene epoch 10.3—4.9 Ma., existing for approximately .-Overview:Borophagus, like other...

     existed for
  • Borophagus pugnator
    Borophagus pugnator
    Borophagus pugnator is an extinct species of the genus Borophagus of the subfamily Borophaginae, a group of canids endemic to North America from the early Miocene epoch through the late Miocene epoch 23.3—4.9 Ma...

     existed for (synonymous with Osteoborus galushai)
  • Borophagus secundus
    Borophagus secundus
    Borophagus secundus is an extinct species of the genus Borophagus of the subfamily Borophaginae, a group of canids endemic to North America from the Early Miocene epoch through the Late Miocene epoch...

    existed for (synonymous with Hyaenognathus cyonoides, Hyaenognathus direptor)

Existence based on age of fossil collections and recombination with other species.

Further reading



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