An ancient crocodile species that lived on our planet around 120 million years ago may have walked on their 2 hind legs just like a T-Rex.

Their work is based on an analysis of large, well-preserved footprints that were discovered at the Sacheon Jahye-ri excavation site in South Korea.

The researchers first thought the fossilized foot impressions belonged from another ancient reptile known as the pterosaur.

Further investigations revealed the footprints to have a heel to toe impressions, which the paleontologists believe were unlikely to have been made by the flying reptiles.

Dr. Anthony Romilio, who is from the University of Queensland in Australia and an author of the study, said:

At one site, the footprints were initially thought to be made by a giant bipedal pterosaur walking on the mudflat, we now understand that these were bipedal crocodile prints.

The researching team also initially questioned the absence of handprints from the trackways, given that modern crocodiles are 4 legged or are quadrupedal creatures.

However, fine details of the toe-pads and scales of the creatures helped the researchers preserve at the site solve the big question.

Dr. Anthony said:

The footprints measure around 24 centimetres, suggesting the track-makers had legs about the same height as human adult legs. These were long animals that we estimate were over three metres in length.

Professor Kyung Soo Kim, a led research from the Chinju National University of Education, said that the footprints indicate that the animal was walking just like 2 legged dinosaurs.

The impressions at the Sacheon Jahye-ri site showed clear heel impressions, which are very similar to the ones that crocodiles have.

Dr. Anthony said:

Dinosaurs and their bird descendants walk on their toes. Crocodiles walk on the flat of their feet leaving clear heel impressions, like humans do.

The marks are dated between 110 to 120 million years old. The footprints are thought to belong to a new species of the crocodylomorph.

The crocodylomorph is ancestors of the modern-day crocodiles and alligators.

However, the trackways showed the animals to have a narrower stance than the crocodiles that we have today.

Professor Kim said:

Typical crocodiles walk in a squat stance and create trackways that are wide.n Oddly, our trackways are very narrow looking – more like a crocodile balancing on a tight-rope. When combined with the lack of any tail-drag marks, it became clear that these creatures were moving bipedally.

The findings are currently published in the journal Scientific Reports.