Oldest bat skeletons ever found described from Wyoming fossils
52-million-year-old fossils support idea that bats diversified rapidly on multiple continents during the Eocene

Date:
April 13, 2023
Source:
American Museum of Natural History
Summary:
Scientists have described a new species of bat based on the oldest
bat skeletons ever recovered. The study on the extinct bat, which
lived in Wyoming about 52 million years ago, supports the idea that
bats diversified rapidly on multiple continents during this time.


Facebook Twitter Pinterest LinkedIN Email
FULL STORY ========================================================================== Scientists have described a new species of bat based on the oldest
bat skeletons ever recovered. The study on the extinct bat, which
lived in Wyoming about 52 million years ago, supports the idea that
bats diversified rapidly on multiple continents during this time. Led
by researchers at the American Museum of Natural History and Naturalis Biodiversity Center in the Netherlands, the study is published today in
the journal PLOS ONE.


========================================================================== There are more than 1,460 living species of bats found in nearly every
part of the world, with the exception of the polar regions and a few
remote islands. In the Green River Formation of Wyoming -- a remarkable
fossil deposit from the early Eocene -- scientists have uncovered over
30 bat fossils in the last 60 years, but until now they were all thought represent the same two species.

"Eocene bats 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, Icaronycteris index,
up until about 20 years ago, when a second bat species belonging to
another genus was discovered," said study co-author Nancy Simmons, curator-in-charge of the Museum's Department of Mammalogy, who helped
describe that second species in 2008. "I always suspected that there
must be even more species there." In recent years, scientists from the Naturalis Biodiversity Center started looking closely at Icaronycteris
index by collecting measurements and other data from museum specimens.

"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 learned about a new skeleton that
diverted our attention." 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 expansive 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 gunnelliin 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 I. gunnelli fossils represent the oldest bat skeletons ever found.

"The Fossil Lake deposits of the Green River Formation are simply amazing because the conditions that created the paper-thin limestone layers also preserved nearly everything that settled to the lake's bottom," said Arvid Aase, park manager and curator at the Fossil Butte National Monument,
in Wyoming. "One of these bat specimens was found lower in the section
than all other bats, making this species older than any of the other bat species recovered from this deposit." While the I. gunnelli skeletons 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 around the world.

"This is a step forward in understanding what happened in terms of
evolution and diversity back in the early days of bats," Simmons said.

* RELATED_TOPICS
o Plants_&_Animals
# New_Species # Endangered_Animals # Evolutionary_Biology
# Wild_Animals
o Fossils_&_Ruins
# Fossils # Ancient_DNA # Evolution # Paleontology
* RELATED_TERMS
o Bat o Homo_(genus) o Ichthyosaur o Mammoth o
Endangered_species o Homo_habilis o Rodent o Dinosaur

========================================================================== Story Source: Materials provided by
American_Museum_of_Natural_History. Note: Content may be edited for
style and length.


========================================================================== Journal Reference:
1. Tim B. Rietbergen, Lars W. van den Hoek Ostende, Arvid Aase,
Matthew F.

Jones, Edward D. Medeiros, Nancy B. Simmons. The oldest known
bat skeletons and their implications for Eocene chiropteran
diversification.

PLOS ONE, 2023; 18 (4): e0283505 DOI: 10.1371/journal.pone.0283505 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2023/04/230413011801.htm

--- up 1 year, 6 weeks, 3 days, 10 hours, 50 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)