A recent study has placed Macrauchenia patachonica — ancient herbivores that had rhino-like feet, but long giraffe-like necks and antelope-like heads — in a sister lineage to one that includes horses, the New York Times reports.
During his Beagle voyage, Charles Darwin uncovered Macrauchenia fossils in Patagonia, but he and others were stumped when they tried to classify them. Over the years, the Times says Macrauchenia have been placed alongside hippos, but also with camels or aardvarks. Macrauchenia went extinct some 12,000 years ago.
In a recent Nature Communications study, researchers led by University of Potsdam's Michael Hofreiter sequenced the mitochondrial genomes of six Macrauchenia bone samples and were able to reconstruct about 80 percent of it.
Their subsequent phylogenetic analysis placed Macrauchenia as a sister taxon to Perissodactyla, which includes odd-toed ungulates like horses and rhinos. They further estimated that Macrauchenia split from Perissodactyla some 56 million to 78 million years ago. The Times notes that their findings corroborate that of a 2015 study that analyzed ancient proteins.
A group that "was basically homeless has now found its place," Hofreiter tells the Times.