In an unusual turn of events, science seeks the help of art in confirming the existence of an extinct hybrid species between ancient cows and steppe bison. The species is believed to be the missing link on the evolutionary lineage of European bison.

Scientists have been long mystified by the sudden appearance of European bison almost 12,000 years ago, about 3,000 years after the extinction of their ancestors, the steppe bison. The sudden appearance of the European bison is not the only thing baffling scientists. The mitochondrial DNA of the European bison shows that it is closely related to cows.

Now, a study published in the journal Nature Communication sheds some light in the mystery of European bison evolution. For the study, the researchers ground up ancient bone fragments and sequenced the full DNA.

Their DNA analysis revealed that a new hybrid species between male steppe bison and female Aurochs, an extinct ancestors of modern cows. The previously unknown hybrid species appeared about 120,000 years ago and have survived for thousands of years.

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"It is unexpected that such a hybridization event would give rise to a new species out-competing both its parent species, probably by adapting better to environmental changes at the time," said Julien Soubrier, a researcher at the University of Adelaide, Australia and co-author of the study, in a report from New York Times.

However, without any skull remains and other bones to reconstruct the body shape of the hybrid species, the researchers were not able to reconstruct what the animal looks like. During this time, the researchers turned to ancient cave painting for help.

Ancient humans during the Stone Age have painted two distinct types of bison on the walls of European caves. Researchers claim that these ancient hunters could not have painted two very different body shapes of bison using only one model. One of the paintings represents the extinct steppe bison, while the other one represents the newly discovered hybrid species. The two paintings are remarkably detailed and dates back about 20,000 years ago.