On October 1, 2024, for the first time in human history, Colossal successfully restored a once-eradicated species through the science of de-extinction. After a 10,000+ year absence, our team is proud to return the dire wolf to its rightful place in the ecosystem. Colossal’s innovations in science, technology and conservation made it possible to accomplish something that's never been done before: the revival of a species from its longstanding population of zero.
(Aenocyon dirus[10] /iːˈnɒkaɪ.ɒn ˈdaɪrəs/) is an extinct species of canine which was native to the Americas during the Late Pleistocene and Early Holocene epochs (125,000–10,000 years ago). The species was named in 1858, four years after the first specimen had been found. Two subspecies are recognized: Aenocyon dirus guildayi and Aenocyon dirus dirus. The largest collection of its fossils has been obtained from the Rancho La Brea Tar Pits in Los Angeles.
Dire wolf remains have been found across a broad range of habitats including plains, grasslands, and some forested mountain areas of North America and the arid savanna of South America. The sites range in elevation from sea level to 2,255 meters (7,400 ft). Dire wolf fossils have rarely been found north of 42°N latitude; there have been only five unconfirmed records above this latitude. This range restriction is thought to be due to temperature, prey, or habitat limitations imposed by proximity to the Laurentide and Cordilleran ice sheets that existed at the time.
The dire wolf was about the same size as the largest modern forms of gray wolf (Canis lupus): the Yukon wolf and the northwestern wolf. A. d. guildayi weighed on average 60 kilograms (132 lb) and A. d. dirus was on average 68 kg (150 lb). Its skull and dentition matched those of C. lupus, but its teeth were larger with greater shearing ability, and its bite force at the canine tooth was stronger than any known Canis species. These characteristics are thought to be adaptations for preying on Late Pleistocene megaherbivores; in North America, its prey is known to have included western horses, ground sloths, mastodons, ancient bison, and camels. Dire wolves lived as recently as 10,000 years ago, according to dated remains. Its extinction occurred during the Quaternary extinction event, disappearing along with its main prey species; its reliance on megaherbivores has been proposed as the cause of its extinction, along with climatic change and competition with other species, or a combination of those factors.
Taxonomy
From the 1850s, the fossil remains of extinct large wolves were being found in the United States, and it was not immediately clear that these all belonged to one species. The first specimen of what would later become associated with Aenocyon dirus was found in mid-1854 in the bed of the Ohio River near Evansville, Indiana. The fossilized jawbone with cheek teeth was obtained by geologist Joseph Granville Norwood from an Evansville collector, Francis A. Linck. Paleontologist Joseph Leidy determined that the specimen represented an extinct species of wolf and reported it under the name of Canis primaevus.[4] Norwood's letters to Leidy are preserved along with the type specimen (the first of a species that has a written description) at the Academy of Natural Sciences of Philadelphia. In 1857, while exploring the Niobrara River valley in Nebraska, Leidy found the vertebrae of an extinct Canis species that he reported the following year under the name C. dirus.[1] The name C. primaevus (Leidy 1854) was later renamed Canis indianensis (Leidy 1869) when Leidy found out that the name C. primaevus had previously been used by the British naturalist Brian Houghton Hodgson for the dhole.[5]