We recently published a paper clarifying the origins of a distinctive group of Ice Age horses, the New World Stilt-legged horses. These horses have very distinctive metapodials that when you see them in the field they jump out as very thin relative to the more robust form of the common Equus lambei forms we commonly find. Pete Heintzman, who was a post-doc with Beth Shapiro’s group and working on some of our Klondike materials in the Yukon collection along with some fossils we recovered in 2010, isolated mitochondrial and nuclear DNA from these fossils and showed that the stilt-legged horses were not related to the living Asiatic asses such as the Tibetan Kulan or Persian Onager, but rather their own separate New World branch of horses. And importantly not just a new species, but actually a whole new genus that we call Haringtonhippus after UofA Alum and palaeontologist-extraordinaire C.Richard Harington from the Canadian Museum of Nature who first described the Yukon horses.
Pete wrote a popular version of the story here.