The fossilized remains of an ancient rodent are not only an astonishing find for its significance, but for its level of pristine condition.

According to Discovery News, authors of a study published in the journal Nature aged the Spinolestes xenarthrosus at 125 million years old, making it the earliest example of a mammal with a hairy exterior by some 60 million years. Discovered in 2011, the fossil showed evidence of a spine, hair follicles, fur, and organs.

"Spinolestes is a spectacular find. It is stunning to see almost perfectly preserved skin and hair structures fossilized in microscopic detail in such an old fossil," study co-author Zhe-Xi Luo, a professor of organismal biology and anatomy at the University of Chicago, said in a press release. "This Cretaceous furball displays the entire structural diversity of modern mammalian skin and hairs."

The fossil pushes back the timeline on when hairy mammals were roaming the Earth and Spinolestes xenarthrosus confirms they lived alongside dinosaurs. The animal belongs to a now-extinct lineage known as triconodonts, which resemble modern-day rodents.

"Spinolestes shows remarkable soft-part preservation," study lead author Thomas Martin, a paleontologist at the University of Bonn, told Discovery News. "In the chest, lung tissue has been fossilized that shows the branched pattern of the airways and the fine terminal bulbs typical for lung tissue.

"There is also a brownish-red spot in the abdominal cavity just behind the lung tissue, which derives from the liver (liver tissue is very rich in iron and its fossilized remainders therefore have a reddish-brown color). The lung and liver are in the exact anatomical position, clearly separated from each other, which indicates the presence of a diaphragm in between, like in modern mammals. The breathing pattern of Spinolestes therefore was like in modern mammals."