A 135-million-year-old fossil dinosaur caught
apparently taking a nap with its head tucked under its forearm has
been discovered by scientists in China. It is the earliest known
example of an animal unearthed in a bird-like repose.
A Nature magazine report says the find suggests the
characteristic sleeping posture probably first arose in the dinosaur
ancestors of modern birds.
Mei long, which means "soundly sleeping
dragon", was pulled out of the famous fossil beds of Liaoning
Province. This is the location in China where so many feathered
dinosaurs have been discovered - astonishing finds that have fuelled
the theory that modern birds can trace their lineage to the
"terrible lizards" that once ruled the Earth.
Mei long is described in Nature by Xing Xu,
from the Chinese Academy of Sciences in Beijing, and Mark Norell, of
the American Museum of Natural History.
Only last week, these researchers were reporting
the discovery of a fluffy-feathered cousin of the mighty
Tyrannosaurus rex - another fossil unearthed in Liaoning. The
scientists can tell from the mechanics of Mei long's skeleton
that the posture it died in was one it would habitually take up -
this was no accidental death pose.
Professor Xu speculates that the dinosaur may have
been killed by poison gas from the volcanic eruption that then
buried it in ash. "Exactly how volcanic activity captured the life
posture, we don't know," Professor Xu said. "There are many
possibilities. For example, volcanic gas cut off the oxygen and the
animal died sleeping, peacefully. Then, later, the body was covered
quickly by ash."
Whatever the cause of death, it must have been
quite sudden. Other dinosaurs discovered in the vicinity but not yet
described in scientific literature also capture living behaviours,
Professor Xu says. Mei long was found sitting squarely on its
hind limbs. Its front legs are extended around the body, with the
head tucked backwards on the left side.