In a 2013 paper, researchers reported on the discovery the oldest known big cat.
The cat was found in the Kiang Valley in Tibet.
Layers of rock have revealed a trove of fossils.
The skull emerges
In 2010, the team, led by Z. Jack Tseng, uncovered the skull of a an ancient pantherine.
By analyzing the orientation of magnetic minerals in the nearby rock, the team was able to determine that the cat lived between 5.9 and 4.1 million years ago.
Follow-up trips revealed several more fossils fro the ancient cat.
Here, the researchers excavate at the site.
Despite living at least 4 million years ago, the ancient cat didn't look too different from living big cats such as snow leopards.
The hole where the cat skull was found also contained about 120 other fossils comprising 16 mammal species and one bird.
Here the team unearths the fossils.
By analyzing the bones and comparing it to living and extinct cats, as well as by using genetic data, the team estimates that all cats diverged about 16 million years ago.
The team excavates fossils at the site.
Tia Ghose, Senior Writer
Tia has interned at Science News, Wired.com, and the Milwaukee Journal Sentinel and has written for the Center for Investigative Reporting, Scientific American, and ScienceNow. She has a master's degree in bioengineering from the University of Washington and a graduate certificate in science writing from the University of California Santa Cruz.