Researchers looked at 48 fossils of hooved animals from South America . The species - Toxodon plantensis and Macrauchenia patachonica - were first discovered by Frido Welker and Argentina 180 years ago . Palaeontologists have struggled to decide whether the strange looking animals were more closely related to rodents , camels or elephants . Scientists developed new technique for analysing proteins in bones that can reveal links between animals that have been dead for millions of years . The technique can reach further back in time than ancient DNA analysis . They found that the extinct South American animals were related to horses . The new technique - called proteomics - could revolutionise palaeontology .
Researchers looked at 48 fossils of hooved animals from South America . The species - Toxodon plantensis and Macrauchenia patachonica - were first discovered by Charles Darwin inUruguay and Argentina 180 years ago . Palaeontologists have struggled to decide whether the strange looking animals were more closely related to rodents , camels or elephants . Scientists developed new technique for analysing proteins in bones that can reveal links between animals that have been dead for millions of years . The technique can reach further back in time than ancient DNA analysis . They found that the extinct South American animals were related to horses . The new technique - called proteomics - could revolutionise palaeontology .