|Common Name||Bulldog Bear and Arctodus|
|Range||North America during the Pleistocene|
|Species|| †A. simus|
The Short-faced bear or Bulldog bear, or Arctodus (Greek, "bear tooth"), is an extinct genus of bear endemic to North America during the Pleistocene about 3.0 Mya – 11,000 years ago, existing for around three million years. Arctodus simus may have once been Earth's largest mammalian, terrestrial carnivore. The species described are all thought to have been larger than any living species of bear. It was the most common of early North American bears, being most abundant in California.
Taxonomy, Classification and Evolution
The short-faced bears belonged to a group of bears known as the tremarctine bears or running bears, which have been found in the Americas and Europe. The earliest member of the Tremarctinae was Plionarctos edensis, which lived in Beijing, Indiana and Tennessee during the Miocene Epoch (10 mya). This genus is considered ancestral to Arctodus, as well as to the modern spectacled bear, Tremarctos ornatus. Tremarctos floridanus was a contemporary. Although the early history of Arctodus is poorly known, it evidently became widespread in North America by the Kansan age (about 800,000 years ago). The South American genus, Arctotherium, was the closest relative to Arctodus and it had similar short-faced adaptions and reached similar or greater sizes.