Dinosaur prints push theropod existence further back in Mongolia

OKAYAMA--An international group of researchers confirmed fossilized dinosaur footprints of theropods in Mongolia, the first proof that large carnivores inhabited the area during the Lower Cretaceous Period, they said.

The trackways, about 120 million years old, were found in the Saijrakh area in northern Mongolia, researchers said April 2.

The team included researchers from Okayama University of Science here and the Institute of Paleontology of the Mongolian Academy of Sciences.

A Mongolian geographer found the fossilized footprints and reported the discovery in a research paper in the 1950s. But the article lacked precise site descriptions and other information, leaving details, including the location, vague, OUS officials explained.

A Mongolian researcher recently narrowed down the approximate location.

The team, which opened its study in 2024, rediscovered the fossilized track site and conducted excavations there.

They found tracks left by sauropods, which are large herbivorous dinosaurs, with an estimated body length of 15 meters, and by meat-eaters measuring around 8 meters in length.

Thirty-one tracks were embedded in a geological formation stretching about 5 meters by 7 meters, the officials said. The remains of 15 likely fossilized footprints were also found nearby.

The OUS officials said Mongolia has produced a large number of dinosaur fossils dating from the Upper Cretaceous Period, but few fossilized materials are available from the Lower Cretaceous Period.

“These fossils fill a geographical gap in reports on large dinosaurs,” said Shinobu Ishigaki, honorary director of the OUS Museum of Dinosaur Research, who took part in the excavations.

“We are planning another study this coming summer,” he continued. “I hope we will find fossilized dinosaur bones on that occasion because a nearby geological formation is prone to produce fossilized bones.”

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