are 55 million years old and lived in Wyoming.
A New species of extinct bat has been described with the oldest skeletal remains recovered.corresponding to a specimen that lived 55 million years ago in present-day Wyoming.
The study supports the idea that bats diversified rapidly on several continents during that time.. Led by researchers at the American Museum of Natural History and the Naturalis Biodiversity Center in the Netherlands, the study is published in the journal PLOS ONE.
There is over 1,460 living species of bats found in almost every part of the world.with the exception of the polar regions and some remote islands. In the Green River Formation of Wyoming, a remarkable early Eocene fossil deposit, scientists have discovered more than 30 bat fossils in the past 60 years, but until now they were all thought to represent the same two species.
“Eocene bats from the Green River Formation have been known from the Green River Formation since the 1960s. But, interestingly, most specimens that have come out of that formation were identified as representing a single species, index Icaronycteris, until about 20 years ago, when a second species of bat belonging to another genus,” study co-author Nancy Simmons, curator in charge of the American Museum of Natural History’s Department of Mammalogy, who helped describe that second species in 2008, said in a statement. “I always suspected there must be even more species there.”
In recent years, scientists at the Naturalis Biodiversity Center began to. closely observe the Icaronycteris index. by collecting measurements and other data from museum specimens.
“Paleontologists have collected so many bats that have been identified as index Icaronycteris, and we wondered if there were actually multiple species among these specimens“, said Tim Rietbergen, evolutionary biologist at Naturalis. “Then we learned of a new skeleton that diverted our attention.”
The oldest bat skeletons.
The exceptionally well-preserved skeleton was. collected by a private collector in 2017 and purchased by the Museum.. When researchers compared the fossil to Rietbergen’s extensive dataset, it clearly stood out as. a new species. A second fossil skeleton discovered in the same quarry in 1994 and in the collections of the Royal Ontario Museum was also identified as this new species. The researchers gave these fossils the species name Icaronycteris gunnelli in honor of Gregg Gunnell, a Duke University paleontologist who died in 2017 and made extensive contributions to the understanding of fossil bats and evolution.
Although there are fossil bat teeth from Asia that are slightly older, the two fossils of I. gunnelli represent the oldest bat skeletons ever found. “One of these bat specimens was found lower in section than all other bats, making this species older than any of the other bat species recovered from this deposit.”
While the skeletons of I. gunnelli are the oldest bat fossils from this site, they are not the most primitive, supporting the idea that Green River bats evolved separately from other Eocene bats worldwide. “This is a step forward in understanding what happened in terms of evolution and diversity in the early days of bats,” Simmons said.
