Short answers, pulled from the story.
The dire wolf (Aenocyon dirus) is an extinct species of canine native to the Americas during the Late Pleistocene and Early Holocene epochs, from approximately 125,000 to 10,000 years ago. It was about the same size as the largest modern gray wolves, with the subspecies A. d. dirus averaging 68 kg.
The first dire wolf specimen was found in mid-1854 in the bed of the Ohio River near Evansville, Indiana. Geologist Joseph Granville Norwood obtained the fossilized jawbone from a local collector named Francis A. Linck and passed it to paleontologist Joseph Leidy, who identified it as an extinct wolf species.
In 2021, researchers sequenced nuclear DNA from five dire wolf fossils dating from 13,000 to 50,000 years ago. The sequences showed the dire wolf last shared a common ancestor with wolf-like canines 5.7 million years ago, confirming it as a highly divergent lineage and supporting placement in the separate genus Aenocyon, as paleontologist John Campbell Merriam had proposed in 1918.
Isotope analysis of La Brea specimens indicates the dire wolf primarily fed on juvenile bison and camels, with Harlan's ground sloth as a secondary prey, and occasionally scavenged beached whales along the Pacific coast. Evidence from mandible shape and tooth wear indicates it was a pack hunter, and its estimated preferred prey fell in the 300 to 600 kg range.
The dire wolf disappeared during the Quaternary extinction event around 12,700 years before present, when 90 genera of large mammals also became extinct. Its reliance on megaherbivore prey, which were vanishing at the same time, is a leading explanation, alongside climate change and competition. Reproductive isolation from Eurasian canids for 5.7 million years may also have prevented the dire wolf from acquiring disease resistance through hybridization, a survival route available to gray wolves and coyotes.
In April 2025, Colossal Biosciences announced three genetically modified wolf pups -- Romulus, Remus, and Khaleesi -- produced by making 20 edits to 14 genes in gray wolf cells to reflect dire wolf traits. The IUCN Species Survival Commission Canid Specialist Group officially declared that the animals are neither dire wolves nor proxies of dire wolves. In May 2025, Colossal's chief scientist Beth Shapiro described them as 'grey wolves with 20 edits.'