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Wow - this is ultra fascinating.
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December 13, 2006
Flying Mammal Found From 125 Million Years Ago
By JOHN NOBLE WILFORD
Scientists have discovered an extinct animal the size of a small squirrel that
lived in China at least 125 million years ago and soared among the trees. It is
the earliest known example of gliding flight by mammals, and the scientists say
it shows that mammals experimented with aerial life about the same time birds
first took to the skies, perhaps even earlier.
>From an analysis of the fossil, the researchers concluded that this gliding
>mammal was unrelated to the modern flying squirrel and unlike any other animal
>in the Mesozoic, the period best known for dinosaurs living in the company of
>small and unprepossessing mammals. They announced today that the species
>qualified as a member of an entirely new order of mammals.
Richard L. Cifelli, a paleontologist at the Oklahoma Museum of Natural History
in Norman who reviewed the findings for publication, said this "wholly
unexpected diversity of something adapted for gliding at this early time is
absolutely astonishing."
Until a couple of years ago, Dr. Cifelli said, most scientists held the view
that such early mammals were simple shrew-like creatures that cowered in the
shadows of the dominant dinosaurs, and now "this adds a new dimension to our
knowledge of early mammals."
Until now, the earliest identified gliding mammal was a 30-million-year-old
extinct rodent. The first known modern bat, which is capable of powered flight,
dates to 51 million years ago, but it is assumed that proto-bats were probably
gliding much earlier.
Archaeopteryx, the earliest known bird, lived about 145 million years ago,
though scientists are not sure if it could flap its feathered wings in fully
powered flight. But it lived about the time birds did take off in flight.
The mammal discovery, described in Thursday's issue of the journal Nature, was
made last year in Inner Mongolia, a region of northern China. Farmers found the
delicate fossil, embedded in sandstone, and brought it to the attention of the
Institute of Vertebrate Paleontology and Paleoanthropology in Beijing.
On a visit there late last winter, Jin Meng, an associate curator of
paleontology at the American Museum of Natural History in Manhattan, examined
the specimen. He saw the sharp and diverse teeth of an insectivore. He then
detected striations in the fossil - clear traces, he said, of hair covering a
stretch membrane from fore to hind limbs that was the airfoil to support and
give lift for the animal to glide.
"This was just totally out of nowhere," Dr. Meng said in an interview at the
museum this week, while pointing to the fossil's telling features.
In the journal report, Dr. Meng and colleagues wrote, "This discovery extends
the earliest record of gliding flight for mammals at least 70 million years
earlier in the geological history and demonstrates that mammals were diverse in
their locomotor strategies and life styles."
The co-authors, who are researchers at the institute, are Yaoming Hu, Yuanqing
Wang, Xiaolin Wang and Chuankui Li. . They have named the mammal
Volaticotherium antiquius, meaning "ancient gliding beast."
A paleontologist not involved in the research, Zhe-Xi Luo of the Carnegie
Museum of Natural History in Pittsburgh, said the discovery contributed more
evidence that "mammals started the invasion of diverse niches long before the
extinction of dinosaurs," which occurred 65 million years ago.
Only last February, Dr. Luo reported finding fossils of a swimming, fish-eating
beaverlike animal that lived in China 164 million years ago. The discovery was
made at the Daohugou site, where the gliding mammal was uncovered.
"The semi-aquatic mammal Castorocauda and the new gliding mammal," Dr. Luo
said, "literally stretch the boundary of paleontologists' imagination about
what would be possible for the earliest mammals."
Dr. Meng's team said tests produced inconsistent dates for the new specimen,
ranging from as recent as 125 million years ago to as ancient as 164 million.
The older date may be more probable, other scientists said, and would put the
aerial life of the mammal even earlier than known bird flight.
In their study of the fossil, Dr. Meng and his associates noted that the mammal
was about half the length of the squirrels frolicking in Central Park, across
from the museum. The animal had a long, stiff tail that served as a stabilizing
rudder for gliding flight. The impressions of fur on the gliding membrane, or
patagium, and other parts of its body preserve some of the most ancient
examples of mammalian skin covering.
The paleontologists surmised that the gliding behavior enabled the small animal
to travel from tree to tree in relative safety, above most of its predators,
and hunt insects over a wider area.
"We have very little fossil record of mammalian flight, and suddenly this one
comes along at such an early time," Dr. Meng said. "Now the question is, what
happened to this group between then and now?"
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