Fossilized mammal skeleton from the dinosaur era found in central Japan

The partial remains of a fossilized skeleton of a herbivorous mammal has been discovered in a layer of earth from the Lower Cretaceous, about 120 million years ago, in Katsuyama, Fukui Prefecture, researchers announced Saturday.

This sketch shows what the rare herbivorous mammal, whose fossilized bones were found in Katsuyama, 
Fukui Prefecture, two years ago, may have looked like 120 million years ago [Credit: Kyodo]

It is rare that an entire fossil of a mammal from the era of the dinosaurs is found, according to Fukui Prefectural University and the Fukui Prefectural Dinosaur Museum.

The skeleton was discovered in June 2014 by Kakeru Funato, then an elementary school student in the fourth grade, who was attending a fossil excavation event in the Katsuyama Dinosaur Forest Park.

A computerized tomography examination by the university and the museum determined that it was the skeleton of a small grass-eating mammal from an extinct group called Multituberculata, which had similar characteristics to Rodentia.

The mudstone that contained a fossil of a rare mammal from 120 million years ago is seen in this photo 
[Credit: Fukui Prefectural University/Fukui Prefectural Dinosaur Museum/Kyodo]

“A fossil skeleton of a Multituberculata mammal is very rare,” Kazunori Miyata, associate professor of Fukui Prefectural University, said. “It will serve as a very important sample that helps unravel the diversification and evolution of Multituberculata mammals.”

The animal is estimated to have had a body length of about 13 centimeters when it was alive, according to the museum and the university. The portion of the well-preserved fossil is 5 centimeters long, 2.6 cm wide and 1.3 cm in height.

Judging from its teeth and body size, it might be a species that had never been discovered before, the researchers said.

This illustration shows the fossilized skeleton of a rare herbivorous mammal from the dinosaur era. 
The skeleton parts that were discovered in Katsuyama, Fukui Prefecture, are displayed in gray 
[Credit: Kyodo]

In the Katsuyama park, rocks are brought in from an excavation site in the city so the general public, including children, can experience what it is like to be a paleontologist. Funato, the 11-year-old boy from the city of Gifu, took part in the event with other members of his family.

He discovered the rare find after cracking into a rock.

“When I found it, I thought it might be a discovery of a sort,” he said. “But I’m astonished to learn it was an important enough fossil to make news.”

Source: The Japan Times [June 26, 2016]