Borophagus hilli
Encyclopedia
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 (23.3 Mya) through the Pliocene
epoch (4.9 Mya). Borophagus dudleyi existed for approximately .
-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
, 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
and later by Canis dirus. Early species of Borophagus were placed in the genus Osteoborus until recently, but the genera
are now considered synonyms. Borophagus hilli possibly led a hyena-like lifestyle scavenging carcasses of recently dead animals.
. Its crushing premolar
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
, although it was much more powerfully built.
et al. in 1999.
to southeastern Washington, from Idaho
to New Mexico
to Texas
. Specimens were also found as far south as the southern tip of Baja, Mexico
Existence based on age of fossil collections and recombination with other 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 early 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 (23.3 Mya) through 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 (4.9 Mya). Borophagus dudleyi existed for approximately .
Overview
Borophagus hilli was named by C. S. Johnston in 1939. Borophagus dudleyi, like other Borophaginae, are loosely known as "bone-crushing" or "hyenaHyena
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 hilli 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 scavengerScavenger
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 hilli were measured by Legendre and Roth for body mass.- Specimen 1: 61 kg (134.5 lb)
- Specimen 2: 57.7 kg (127.2 lb)
Recombination
Borophagus hilli was synonymized subjectively with Borophagus direptor by Kurten and Anderson in 1980 as well as synonymous with Osteoborus crassapineatus, Osteoborus progressus. It was recombined as Borophagus hilli by Xiaoming WangXiaoming Wang
Xiaoming Wang is a noted paleontologist and geologist born in People's Republic of China living in the United States.-Area of expertise:Dr. Wang specializes in the fossil evolution, systematics, and phylogeny of mammals of the Cenozoic...
et al. in 1999.
Fossil distribution
Borophagus hilli fossil specimens are widespread from east central FloridaFlorida
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...
to southeastern Washington, from Idaho
Idaho
Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....
to New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
to Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
. Specimens were also found as far south as the southern tip of Baja, Mexico
Species
- Borophagus dudleyiBorophagus dudleyiBorophagus 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 diversidensBorophagus diversidensBorophagus 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 littoralisBorophagus littoralisBorophagus 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 orcBorophagus orcBorophagus orc is an extinct species of the genus Borophagus of the subfamily Borophaginae, a group of canids endemic to North America from the late Zanclean stage of the Pliocene epoch through the Hemphillian stage of the Miocene epoch...
existed for - Borophagus parvusBorophagus parvusBorophagus 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 pugnatorBorophagus pugnatorBorophagus 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 secundusBorophagus secundusBorophagus 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
- Russell Hunt, "Ecological Polarities Of the North American Family Canidae: A New Approach to Understanding Forty Million Years of Canid Evolution" (Accessed 1/30/06).
- Wang et al., "Phylogenetic Systematics of the Borophaginae (Carnivora:Canidae)." Bulletin of the American Museum of Natural History, No. 243, Nov. 17 1999. (PDF) (Accessed 4/11/06)