The strange-looking Macrauchenia patachonica had the body of a rodent, legs of a camel and the nose of an elephant, a bizarre sight indeed, and its fossilized remains left Darwin bemused. The mysterious creature lived 10,000 years ago and was native to South America, writes Sarah Knapton for The Telegraph. Scientists have now used protein sequencing to determine that the mammal is closely related to horses.
Solving Darwin’s puzzle
“Fitting South American ungulates to the mammalian family tree has always been a major challenge for paleontologists, because anatomically they were these weird mosaics, exhibiting features found in a huge variety of quite unrelated species living all over the place,” said Ross MacPhee, study co-author and curator in the American Museum of Natural History’s Department of Mammalogy.
“This is what puzzled Darwin and his collaborator Richard Owen so much in the early 19th century. With all of these conflicting signals, they couldn’t say whether these ungulates were related to giant rodents, or elephants, or camels–or what have you.”
Originally the team tried to sequence the ancient animal’s DNA, but found it to be too degraded to be of use. Their next approach involved looking at protein in the bone collagen, whose chemical structure is governed by DNA.
“People have been successful in retrieving collagen sequences from specimens dating up to 4 million years old, and this is just the start,” said professor Matthew Collins of the University of York, whose lab carried out the sequencing work. “On theoretical grounds, with material recovered from permafrost conditions, we might be able to reach back 10 million years,” he continued.
Darwin’s successors make progress
The scientists selected the best bone specimens from dozens of fossils of Macrauchenia patachonica, and “were able to obtain roughly 90 percent of the collagen sequence for both species,” according to lead author Frido Welker, a Ph.D. student at the Max Planck Institute for Evolutionary Anthropology and the University of York.
“This opens the way for various other applications in paleontology and paleoanthropology, which we are currently exploring.”
Using the technique, researchers demonstrated the the closest living relatives were perissodactyls, a group which counts horses, rhinos and tapirs among its number, solving the conundrum which puzzled Darwin.