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Finally, a break from tradition...
Xu X., M. A. Norell. 2004. A new troodontid dinosaur from China with
avian-like sleeping posture. _Nature_ 431:838-841.
[doi:10.1038/nature02898] (w/ suppl. info.)
"Discovering evidence of behaviour in fossilized vertebrates is rare.
Even rarer is evidence of behaviour in non-avialan dinosaurs that
directly relates to stereotypical behaviour seen in extant birds
(avians) and not previously predicted in non-avialan dinosaurs. Here we
report the discovery of a new troodontid taxon from the Early
Yixian Formation of western Liaoning, China. Numerous other
three-dimensionally preserved vertebrate fossils have been recovered
recently at this locality, including some specimens preserving
behavioural information. The new troodontid preserves several features
that have been implicated in avialan origins. Notably, the specimen is
preserved in the stereotypical sleeping or resting posture found in
extant Aves. Evidence of this behaviour outside of the crown group Aves
further demonstrates that many bird features occurred early in
Yeah, another troodontid (*Mei long*; in Chinese, literally, "soundly
sleeping dragon" or, in Yoda-talk, "dragon, soundly sleeping") from the
Lujiatun member (informal?) of the Yixian Formation. That makes all three
now described troodontids from the Yixian as the earliest Cretaceous. Even
more weight for *Koparion,* now only about 5-8 million years older. And
yes, there's more. Wait for SVP for more.
Published online: 13 October 2004; | doi:10.1038/news041011-7
Fossil dinosaur slept like a bird
by Michael Hopkin
"Sleeping dragon" may have been trying to stay warm while it snoozed.
The angst-ridden Prince Hamlet described death as an eternal sleep,
fearfully wondering what dreams may come during the everlasting slumber.
So perhaps he would have empathized with a dinosaur newly unearthed in
China: it seems to have been preserved in the act of sleeping.
The dinosaur, named *Mei long,* or 'soundly sleeping dragon', has lain
undisturbed for almost 140 million years. But its sleeping posture is
strikingly similar to that of modern birds, showing that this position
might have evolved before they did.
*M. long* seems to have died with its hindlimbs folded underneath it and
its head tucked under one forelimb, just as birds roost with their head
under their wing. It is the oldest known fossil found in this posture, say
its discoverers, Xing Xu of the Chinese Academy of Sciences in Beijing and
Mark Norell of the American Museum of Natural History, New York, in Nature
The fact that *M. long* seems to have a sleeping habit that is so
similar to that of modern birds means that the two probably share a common
ancestor not much older than the dinosaur itself, the authors add.
It is rare for a fossil to be preserved in a 'life pose', which can tell
us about an animal's behaviour as well as its body. "You're seeing a
snapshot of something that happened millions of years ago," says Norell.
"People who have seen the specimen have been blown away by it."
Fossils that tell us about day-to-day dinosaur life are incredibly
valuable, agrees David Varricchio of Montana State University in Bozeman.
Last month he unveiled an entire fossilized dinosaur family, demonstrating
parental care in these animals (see "Fossil hints at devoted parenting in
'Death poses' are a lot more common than life poses, Varricchio says.
Remains are often contorted by rigor mortis before they are buried and
fossilized, he says.
*M. long* was probably buried alive quickly as a result of an eruption,
Norell speculates. It was found in volcanic sediments in the province of
Liaoning in northeast China. "There's lots of ash in the sediments," he
says. "But it also could have been poisoned by noxious gas such as carbon
monoxide. It's hard to show."
The specimen's birdlike-posture also hints that the animal could have
been warm-blooded, Norell says. Modern birds tuck their heads under one
wing to conserve heat; perhaps *M. long* did the same.
"Warm-bloodedness had to arise someplace," Norell says. "You can't
directly take a fossil's temperature, but it is very closely related to
This closeness is underlined by the dragon's diminutive size. At just 53
centimetres long, the dinosaur supports the theory that the evolution of
flight in birds was helped by the fact that, as a family, they were fairly
The many theories surrounding *M. long* serve to underline Liaoning's
status as perhaps the world's richest treasure trove of fossil dinosaurs.
And Norell should know... he has seen plenty. "I think this is a really
cool fossil," he enthuses, "one of the neatest I've worked on."
Add *Mei long* to the troodontid analyses while you can, Mickey!
Jaime A. Headden
Little steps are often the hardest to take. We are too used to making leaps
in the face of adversity, that a simple skip is so hard to do. We should all
learn to walk soft, walk small, see the world around us rather than zoom by it.
"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)
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