The Fossil Lake deposits of the Green River Formation of Wyoming in the United States have produced nearly 30 bat fossils over the last 50 years. However, diversity has thus far been limited to only two bat species. Now, paleontologists have described a new species of the bat genus Icaronycteris based on two skeletons discovered in the American Fossil Quarry northwest of Kemmerer, Wyoming.
With over 1,400 living species, bats are the second most speciose group of mammals.
They are found all over the world with the exception of polar regions and a few remote islands, and are ecologically highly diverse, occupying a wide variety of habitats and ecological niches.
Bats play a vital role in healthy natural ecosystems and additionally provide many ecosystem services important for human economies (e.g. pest control, pollination, seed dispersal).
They are also the only mammals capable of true powered flight, an adaptation that evolved early in the history of the bat lineage.
The earliest confirmed records of bats are from early Eocene deposits.
“Eocene bats have been known from the Green River Formation since the 1960s,” said Dr. Nancy Simmons, a paleontologist at the American Museum of Natural History.
“But interestingly, most specimens that have come out of that formation were identified as representing a single species, Icaronycteris index, up until about 20 years ago, when a second bat species belonging to another genus was discovered.”
“I always suspected that there must be even more species there.”
The newly-identified species, Icaronycteris gunnelli, lived in North America approximately 52 million years ago.
The animal weighed 22-29 grams, similar to the body mass estimates for Icaronycteris index.
“Paleontologists have collected so many bats that have been identified as Icaronycteris index, and we wondered if there were actually multiple species among these specimens,” said Tim Rietbergen, an evolutionary biologist at Naturalis.
“Then we…
Read the full article here