Fossils have the ability to reveal main aspects of an extinct creature such as its bones, teeth, claws, even soft tissue like fur, skin, feathers, organs, and at times leftovers of its last meal in the gut. Any information about its color has been a trickier question.

But scientists have found a way to answer this question, based on microscopic structures in fossils that divulge pigment. On Monday, they for the first time ever revealed the fur color of extinct mammals: 2 of the earliest-known bats known as Palaeochiropteryx and Hassianycteris. They were reddish brown.

Molecular paleobiologist Jakob Vinther of Britain's University of Bristol said the bats were brown. Vinther also used the technique for studying colors in dinosaurs, fish, amphibians and fossil squid ink.

The method for the first time was described in 2008 about a 105-million-year-old black-and-white striped feather from Brazil. It also showed that a winged dinosaur from China, Microraptor, possessed iridescent feathers.

Virginia Tech paleobiologist Caitlin Colleary said biologists are aware of a number of things regarding living animals because of color. They have got an idea about what sort of environment they lived in, how they protected themselves or how they used to attract mates.

Caitlin Colleary added, “But since so little is preserved in the fossil record, the color of extinct animals has always been left up to artists' interpretations, and important information regarding behavior has been considered inaccessible”.

"Reddish brown melanosomes are little tiny meatballs around 500 nanometers in diameter, while black melanosomes are elongated sausages about a micron in length," Vinther said.