Microtomarctus
Encyclopedia
Microtomarctus is an extinct genus of the Borophaginae
and a small terrestrial
canine
which inhabited most of North America
during the Whitneyan
stage (20.6 Mya) of the Early Miocene
subepoch through the Barstovian
stage (13.6 Mya) of the Middle Miocene
subepoch.
Microtomarctus existed for approximately .
Like other Borophaginae it had powerful, bone crushing jaws and teeth.
, coastal southeast Texas
, California
, New Mexico
, Nevada
and Colorado
.
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:...
and a small terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
canine
Canidae
Canidae is the biological family of carnivorous and omnivorous mammals that includes wolves, foxes, jackals, coyotes, and domestic dogs. A member of this family is called a canid . The Canidae family is divided into two tribes: Canini and Vulpini...
which inhabited most of 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...
during the Whitneyan
Whitneyan
The Whitneyan 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 33,300,000 to 30,800,000 years BP, a period of . It is usually considered to fall within the Early Oligocene...
stage (20.6 Mya) of the Early Miocene
Early Miocene
The Early Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Aquitanian and Burdigalian stages....
subepoch through the Barstovian
Barstovian
The Barstovian 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 16,300,000 to 13,600,000 years BP, a period of . It is usually considered to overlap the Langhian and Serravallian...
stage (13.6 Mya) of the Middle Miocene
Middle Miocene
The Middle Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene....
subepoch.
Microtomarctus existed for approximately .
Like other Borophaginae it had powerful, bone crushing jaws and teeth.
Morphology
Fossil specimens of two individuals' body mass were examined by Legendre and Roth. The first specimen was estimated to weigh 7.06 kg (15.5 lbs). The second specimen was estimated to weigh 6.80 kg (14.9 lbs).Species
M. conferta (synonymous with Tomarctus paulus) was named by Matthew in 1918. In 1924, Matthew recombined it and named it Tomarctus confertus. It again was verified by Matthew in 1924, Green (1948), Hough (1948) and Downs in 1956. X. Wang restudied the specimens and recombined it as Microtomarctus conferta.Fossil distribution
Fossil specimens were found in NebraskaNebraska
Nebraska is a state on the Great Plains of the Midwestern United States. The state's capital is Lincoln and its largest city is Omaha, on the Missouri River....
, coastal southeast 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...
, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, 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...
, Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
and Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
.