Borophagus secundus

Borophagus secundus; Temporal range: Early to Late Miocene, 23.0–5.3 Ma PreꞒ Ꞓ O S D C P T J K Pg N
	Borophagus secundus skull
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora
Family:	Canidae
Genus:	† Borophagus
Species:	†B. secundus
Binomial name
	†Borophagus secundus; VanderHoof, 1931
Synonyms
	†Hyaenognathus cyonoides; †Hyaenognathus direptor;

Last updated May 12, 2023

Borophagus secundus ("devouring glutton") 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 (23.0 Mya) through the Late Miocene epoch (5.3 Mya). Borophagus secundus existed for approximately 17.7 million years.^[2]

Overview

Borophagus secundus, like other Borophaginae, are loosely known as "bone-crushing" or "hyena-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 . Early species of Borophagus were placed in the genus Osteoborus until recently, but the genera are now considered synonyms.^[1]

Taxonomy

Like other members of its genus, B. secundus had a bulging forehead and powerful jaws; it was considered to be probably a scavenger by paleontologists in the past.^[3] Its crushing premolar teeth and strong jaw muscles would have been used to crack open bone, much like the hyena of the Old World. However, B. secundus fossils are so abundant and geographically widespread that some paleontologists now argue that it must have been the dominant carnivore of its time, and thus an active predator because carrion feeding alone could not have sustained such a large population.^[4] They note that not all carnivores with bone-cracking ability are scavengers, such as the modern spotted hyena; instead, they interpret the bone-cracking ability as an adaptation to social hunting where complete utilization of a carcass was favored.^[4]

The adult animal is estimated to have been about 80 cm in length, similar to a coyote, although it was much more powerfully built.^[5]

Fossil distribution

Borophagus secundus fossil specimens are very widespread from Honduras and El Salvador to central Mexico, Oklahoma panhandle, central and southern California, Nebraska, Kansas, and northern New Mexico.

Related Research Articles

Canidae is a biological family of dog-like carnivorans, colloquially referred to as dogs, and constitutes a clade. A member of this family is also called a canid. The family includes three subfamilies: the extant Caninae and the extinct Borophaginae and Hesperocyoninae. The Caninae are known as canines, and include domestic dogs, wolves, coyotes, foxes, jackals and other extant and extinct species.

Borophagus is an extinct genus of the subfamily Borophaginae, a group of canids endemic to North America from the Middle Miocene epoch through the Early Pleistocene epoch 12—1.8 Mya.

Aelurodon is an extinct canid genus of the subfamily Borophaginae which lived from the Barstovian land mammal age of the middle Miocene to the late Miocene epoch. Aelurodon existed for approximately 10.7 million years.

The extinct Borophaginae form one of three subfamilies found within the canid family. The other two canid subfamilies are the extinct Hesperocyoninae and extant Caninae. Borophaginae, called "bone-crushing dogs", were endemic to North America during the Oligocene to Pliocene and lived roughly 34—2.5 million years ago, existing for about 33.5 million years.

Epicyon is a large, extinct, canid genus of the subfamily Borophaginae, native to North America. Epicyon existed for about 15 million years from the Hemingfordian age of the Early Miocene, to the Hemphillian of the Late Miocene. Epicyon is the largest known canid of all time, with the type species reaching 2.4 m (7.9 ft) in length, 90 cm (35 in) in shoulder height and approximately 100–125 kg (220–276 lb) in body mass. The largest known humerus specimen belonged to an individual weighing up to 170 kg (370 lb).

Hesperocyon is an extinct genus of canids that was endemic to North America, ranging from southern Canada to Colorado. It appeared during the Uintan age, –Bridgerian age (NALMA) of the Mid-Eocene– 42.5 Ma to 31.0 Ma. (AEO). Hesperocyon existed for approximately 11.5 million years.

Cynodesmus is an extinct genus of omnivorous canine which inhabited North America during the Oligocene living from 33.3—-26.3 Ma and existed for approximately 7 million years.

Tomarctus is a canid genus of the extinct subfamily Borophaginae which inhabited most of North America during the late Early Miocene to the Early Barstovian age of the Middle Miocene. Tomarctus existed for approximately 6.83 million years.

<i>Cynarctus</i> Extinct genus of carnivores

Cynarctus is an extinct genus of the Borophaginae subfamily of canids native to North America. The genus was first founded by W. D. Matthew in 1901, based from a pair of lower jaws, Cynarctus saxitilis, found in the Pawnee Creek Beds of Colorado. It lived during the Middle to Late Miocene 16.0—10.3 mya, existing for approximately 5.7 million years. Fossils have been uncovered in Colorado, California, Maryland, western Nebraska, and Texas. It was likely an omnivore, and lacked the bone-cracking adaptations found in some later borophagines. Newer findings have proved the genus to be described as a large dog-like raccoon, a result from combining characteristics from Canidae with Procyonidae.

Euoplocyon is an extinct genus of the Borophaginae subfamily of canids native to North America. It lived during the Early to Middle Miocene, 20.6—13.6 Mya, existing for about 7 million years. A member of the Borophagini tribe, it was an intermediate-sized canid, with specialisations towards a heavily meat-based diet.

Paratomarctus is an extinct monospecific genus of the Borophaginae subfamily of canids native to North America. It lived from the Middle to Late Miocene, 16.3 – 5.3 mya, existing for approximately 11 million years. It was about the size of a coyote, and was probably a generalised predator, without the specialised adaptations of most later borophagines.

Borophagini is a clade or tribe of the subfamily Borophaginae. This is an extinct group of terrestrial canids that were endemic and widespread throughout North America and Central America which lived during the Geringian stage of the Oligocene epoch to the Zanclean age of the Early Pliocene living 30.8—3.6 Mya existing approximately 27.2 million years.

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 5.4 million years.

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. Borophagus dudleyi existed for approximately 5.4 million years.

Borophagus hilli is an extinct species of the genus Borophagus of the subfamily Borophaginae, a group of canids endemic to North America from the Late Miocene until the Pliocene.

Borophagus diversidens is an extinct species of the genus Borophagus of the subfamily Borophaginae, a group of canids endemic to North America from the late Miocene epoch through the Pliocene epoch 4.9—1.8 Ma.

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. Borophagus littoralis existed for approximately 18.4 million years.

Borophagus orc is an extinct species of the genus Borophagus of the subfamily Borophaginae, a group of canids endemic to North America from the 10.3 Mya to 4.9 Mya. Borophagus orc existed for approximately 5.4 million years.

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—5.3 Ma. Borophagus pugnator existed for approximately 18 million years.

Richard Hall Tedford was Curator Emeritus in the Department of Vertebrate Paleontology of the American Museum of Natural History in New York City, having been named as curator in 1969.

References

1 2 Wang, Xiaoming; Richard Tedford; Beryl Taylor (1999-11-17). "Phylogenetic systematics of the Borophaginae" (PDF). Bulletin of the American Museum of Natural History. 243. Archived from the original (PDF) on 2007-03-20. Retrieved 2007-07-08.
↑ PaleoBiology Database: Borophagus secundus, basic info
↑ Lambert, David (1985). The Field Guide to Prehistoric Life . New York: Facts on File. p. 163. ISBN 0-8160-1125-7.
1 2 Wang, Xiaoming; and Tedford, Richard H. Dogs: Their Fossil Relatives and Evolutionary History. New York: Columbia University Press, 2008. pp112-3
↑ Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 220. ISBN 1-84028-152-9.

Alan Turner, "National Geographic: Prehistoric Mammals" (Washington, D.C.: Firecrest Books Ltd., 2004), pp. 112–114. ISBN 0-7922-7134-3
Xiaoming Wang, "The Origin and Evolution of the Dog Family" Accessed 1/30/06.