Armbruster's Wolf 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 canid

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 was 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...

 and lived during the Irvingtonian

Irvingtonian

The Irvingtonian 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 1,800,000 to 300,000 years BP, a period of . It is usually considered to overlap the Lower Pleistocene and Middle...

 stage of the Pleistocene

Pleistocene

The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....

 epoch 1.8 Mya—300,000 years ago, existing for approximately ..

Origin

Canis armbrusteri is the oldest member of lupus and may have evolved from C. chihliensis in Asia (Tedford, Wang, 182). C. armbrusteri first appears in the Early Pleistocene (Irvingtonian) in the southwestern United States. Remains are often found within the rock strata containing Mammoth

Mammoth

A mammoth is any species of the extinct genus Mammuthus. These proboscideans are members of Elephantidae, the family of elephants and mammoths, and close relatives of modern elephants. They were often equipped with long curved tusks and, in northern species, a covering of long hair...

. It was displaced in the middle section of the continent by the Dire Wolf

Dire Wolf

The Dire Wolf, Canis dirus, is an extinct carnivorous mammal of the genus Canis, and was most common in North America and South America from the Irvingtonian stage to the Rancholabrean stage of the Pleistocene epoch living 1.80 Ma – 10,000 years ago, existing for approximately .- Relationships...

 (C. dirus) with C. armbrusteri pushed eastward until the Late Pleistocene

Late Pleistocene

The Late Pleistocene is a stage of the Pleistocene Epoch. The beginning of the stage is defined by the base of the Eemian interglacial phase before the final glacial episode of the Pleistocene 126,000 ± 5,000 years ago. The end of the stage is defined exactly at 10,000 Carbon-14 years BP...

 (Rancholabrean

Rancholabrean

The Rancholabrean 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 less than 240,000 years to 11,000 years BP, a period of . It is usually considered to overlap the Middle Pleistocene...

 stage) in 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...

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Canis armbrusteri did not give rise to C. dirus (Dire Wolf). The evolutionary origin of C. dirus is unknown but it may be a descendent of the South American C. nehringi.

Taxonomy

Canis armbrusteri was named by J. W. Gidley in 1913. The first fossils were uncovered at Cumberland Cave, Maryland which in an Irvingtonian terrestrial horizon. Fossil distribution is widespread throughout the U.S..

Morphology

Armbruster's Wolf was generally larger and heavier than its older and longer living cousin, Canis lupus. Fossil records and current data show it was as much as 15 kg (33.1 lb) heavier.

Body mass

A specimen was estimated by Legendre and Roth to weigh 63.1 kg (139.1 lb) and another specimen was estimated to weigh 54.4 kg (119.9 lb).

Sister species

Armbruster's Wolf' is considered a sister species of the Dire Wolf

Dire Wolf

The Dire Wolf, Canis dirus, is an extinct carnivorous mammal of the genus Canis, and was most common in North America and South America from the Irvingtonian stage to the Rancholabrean stage of the Pleistocene epoch living 1.80 Ma – 10,000 years ago, existing for approximately .- Relationships...

, one of the most recent evolutionary relatives of the modern wolf, differing from the Gray Wolf

Gray Wolf

The gray wolf , also known as the wolf, is the largest extant wild member of the Canidae family...

 and Dire Wolf by a narrower skull. It is considered to be the closest relative to Canis falconeri

Canis falconeri

Canis falconeri is the relative of Canis armbrusteri which is considered the ancestor of the Dire wolf, one of the most recent evolutionary ancestors to the wolf and differs from the Gray wolf and Dire wolf because of a more narrow skull.Canis armbrusteri is the closest known relative....

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