Feb 08 (NHK) - Japanese researchers believe that a jawbone fossil discovered in Fukui Prefecture in 2019 might be from the earliest mammal to ever live within its shores.
Researchers at Fukui Prefectural Dinosaur Museum have analyzed a lower jaw fossil that was unearthed in June, 2019. It was found in the early Cretaceous stratum, which dates back about 127 million years.
The jaw has three teeth, each measuring 13.1 millimeters long and 5.8 millimeters high.
Researchers suspect that the jawbone belonged to a primitive mammal that was about 16 to 17 centimeters long.
Researchers say Japan's earliest currently known mammal fossil was found in the stratum dating back about 130 to 121 million years.
The latest discovery was excavated from the stratum of almost the same age.
They say that suggests this mammal lived in the same age, or even earlier.
Chief researcher Miyata Kazunori says the specimen is valuable as it suggests a diversity of mammals in the time of dinosaurs.
