Prehistoric creature resembling a hippopotamus, identified by a long-forgotten dinosaur bone

More than 60 years ago, a rare thigh bone was discovered in Japan. At the time, it was thought that the fossil belonged to a dinosaur, but recently, a team of researchers discovered that it belonged to an old hippopotamus-like creature, who lived on Earth long after the dinosaur. extinction of the dinosaurs.

Fossils were discovered in the 1950s by workers building a dam near Tsuchiyu Onsen town in Fukushima, Japan. While the locals did not pay much attention to the discovery, the investigators recovering the bone have clbadified it as belonging to an ancient dinosaur.

The fossil was found on a small village, but in a few years it was part of the city was destroyed because of the fire and the remains were donated to the University of Tsukuba, at Japan. He stayed in a wooden box for decades as part of the geological collection of the university until a group of scientists spotted the strange bone and launched an investigation for to study the origin

As the team reported in an article was accompanied by a handwritten note of the original investigators. Usually, labels with museum fossils like the one studied here carry information about the specimen in question for further research, but in this case nothing was mentioned except the name and local address of the specimen. A person.

to visit the city of Tsuchiyu Onsen. There, they conducted a detailed fieldwork, which consisted of interviewing the locals who lived there and reviewing the archived documents. All the effort, which revealed the "dinosaur" part of the story, led them to the discovery site where they tested rocks containing zircons – a mineral that acts as a time capsule.

After combining the results of the work After studying the other fossils recovered at the site, the team came to the conclusion that the fossil in question came from a marine herbivore of the genus Paleoparadoxia, which has since disappeared. long time. The mammal, as described by the researchers, resembled a modern hippopotamus and lived at least 15.9 million years ago, tens of millions of years later. extinction of the dinosaurs.

The researchers described the fossil as the best-preserved femoral surface of Paleoparadoxia and created a 3D reconstruction of the creature to show what it would have looked like.

In the past, many fossils and postcranial remains linked to the long-vanished genus have been discovered from what is now the Pacific Ocean. It is believed that the plant – eating creature lived between 20 and 10 million years ago and swept the waters between Japan, Alaska and New Mexico. Initial work suggested that these creatures were amphibians, but a more recent badysis supported the idea that they were all marine and that they were walking to the bottom of the seas, feeding on fish. algae and herbs.

The study was titled: "Long Forgotten" dinosaur bone from a museum cabinet, discovered to be a missing mammal emblematic of Japan, Paleoparadoxia (Desmostylia, Mammalia), "was published July 25 in the Royal Society Open Science.