Forgotten fossil rewrites Japan's ancient Cenozoic age of mammals
For more than 100 years, a fossilized femur believed to be from an extinct species of rhinoceros sat on a museum shelf here in Japan.
|A reconstructed image of a Chalicotheriidae by Takashi Oda |
[Credit: Gifu Prefectural Museum]
Officials at the Gifu Prefectural Museum announced July 26 that the femur is the first example of a Chalicotheriidae fossil discovered in Japan.
The new findings were published in the July issue of the U.S. scientific publication Journal of Vertebrate Paleontology.
The fossilized bone was unearthed in Mitake more than 100 years ago and had been in the museum’s collection for decades, thought to be just one of many rhinoceros fossils.
The bone was identified through a collaborative study between Naoto Handa from the Museum of Osaka University, who specializes in vertebrate paleontology, and Soichiro Kawabe, a researcher at the Fukui Prefectural Dinosaur Museum, who was a curator at the Gifu Prefectural Museum when he wrote the paper.
|A fossilized femur of a species from the Chalicotheriidae family that was found more than |
a century ago in Mitaka, Gifu Prefecture [Credit: Gifu Prefectural Museum]
The species is believed to have faced extinction 780,000 years ago or earlier, and there is no close species surviving today.
The femur measures about 60 centimeters in length, and about 10 cm at its widest point. Museum records show that it was found in Mitaka sometime before 1917, but the exact date and location of its discovery remain a mystery.
For almost 100 years, it had been long believed to belong to a species of rhinoceros that once inhabited the area around Mitaka about 18 million years ago.
The collaborative research was undertaken after Handa, who had been studying prehistoric rhinos, visited the museum to conduct research in 2013.
He noticed that the fossilized femur had a different characteristic than other rhinoceros bones, and realized it was closer to the Chalicotheriidae family.
The fossilized femur will be on special display at the museum from Aug. 3 through Sept. 30.
Author: Ryo Yamagishi | Source: The Asahi Shimbun [July 31, 2016]