article_snippet: The four-legged Macrauchenia patachonica, shown in the artists impression above, has baffled scientists since fossils of the species, which died out around 10,000 years ago, were found by Charles Darwin 180 years ago .
article_snippet: The researchers, whose work is published in the journal Nature screened 48 fossils of Toxodon plantensis and Macrauchenia patachonica - the same species that Darwin discovered the remains of in Uraguay and Argentina 180 years ago.
article_snippet: The photograph above shows the skull of a Toxodon plantensis kept at the Natural History Museum in London .
article_snippet: Charles Darwin (right) was baffled by fossils of the Toxodon (shown in the illustration on the right) when Charles Darwin (right) first discovered it and scientists have struggled ever since to work out where it sits in the evolutionary tree .
highlights_snippet: The species - Toxodon plantensis and Macrauchenia patachonica - were first discovered by Charles Darwin inUruguay and Argentina 180 years ago .
  