Oldest known bat fossils discovered in Wyoming are a previously unknown species

Two 52 million-year-old bat skeletons discovered in an historic lake mattress in Wyoming are the oldest bat fossils ever discovered — and so they reveal a new species.

Tim Rietbergen, an evolutionary biologist on the Naturalis Biodiversity Middle in Leiden, the Netherlands, recognized the previously unknown bat species when he started accumulating measurements and different knowledge from museum specimens.