Wikipedia
Palaeochiropteryx is an extinct genus of bat from the Middle Eocene of Europe. It contains two very similar species – Palaeochiropteryx tupaiodon and Palaeochiropteryx spiegeli, both from the famous Messel Pit of Germany. They are usually found complete and exceptionally preserved, even retaining the outlines of their fur, ears, and wing membranes.
They are one of the oldest bats known, existing around 48 million years ago. Despite this, they were already quite advanced, showing evidence of the ability to hunt by echolocation like modern insect-eating bats.
Palaeochiropteryx were small bats, with a wingspan between . Their wings were short but broad, indicating an adaptation for slow but highly maneuverable flight beneath forest canopies and among dense vegetation. They preyed mostly on moths and caddisflies and were probably nocturnal.
It, and the contemporary Hassianycteris, are the first fossil mammals to have their colouration figured out.