Pterosaur embryo found in egg

[bh480@scn.org]

From: Ben Creisler bh480@scn.org
Pterosaur embryo found in egg

Just in case this has not been mentioned here yet, the new 
issue of Nature reports the discovery of a perfect 
pterosaur embryo.
http://www.nature.com/nsu/040607/040607-6.html

Perfect pterosaur found in fossil egg
Find sheds light on prehistoric flying reptiles. 
10 June 2004 
The preserved bones of ancient creatures allow fossil-
hunters to glimpse lives lived millions of years ago. But 
researchers in China have uncovered the remains of a life 
that was snatched away before it had even begun.
The unfortunate creature was a pterosaur, report its 
discoverers Xiaolin Wang and Zhonghe Zhou of the Chinese 
Academy of Sciences in Beijing. This group of flying 
reptiles were contemporaries of the dinosaurs and abounded 
in the Early Cretaceous period when the fossil was 
created, around 121 million years ago.
The embryo is very well formed, which suggests that it was 
probably enjoying its last few days of solitude before 
emerging into the prehistoric world. But it never got the 
chance. Wang and Zhou believe that a natural disaster such 
as a volcanic eruption dealt it a swift death and caused 
the egg to be delicately preserved.
The hapless pterosaur's misfortune is the researchers' 
good luck. The specimen, which includes imprints of wing 
and skin tissue as well as bones and shell, confirms the 
long-standing theory that the creatures laid eggs rather 
than giving birth to live young.
Laid to rest
Uncovered at Jingangshan in the Liaoning province of 
northeastern China, the fossil is the first pterosaur 
embryo ever found. There is no doubt as to its identity: 
its well-developed shoulder and chest bones, and elongated 
fourth finger, mark it out as a pterosaur, the authors 
report in this week's Nature1.
The tiny creature also gives us new insight into pterosaur 
life, says Wang. At just 53 millimetres long and 41 
millimetres wide, it is slightly smaller than a typical 
hen's egg. But the embryo boasts a 27-centimetre wingspan 
that would have more than quadrupled by adulthood.
What's more, says Wang, the baby beast would have been an 
early developer, like many modern bird chicks. "The well 
developed wings suggest that it would have been able to 
fly and feed independently of its parents soon after it 
hatched," he says.
 References 
Wang, X. & Zhou, Z. Nature,429, 623, doi:10.1038/429621a 
(2004)|

Palaeontology: Pterosaur embryo from the Early Cretaceous
XIAOLIN WANG AND ZHONGHE ZHOU
Institute of Vertebrate Paleontology and 
Paleoanthropology, Chinese Academy of Sciences, PO Box 
643, Beijing 100044, China
xlinwang@263.net

Dinosaur embryos have been discovered all over the world, 
but so far no pterosaur embryos have been reported. Here 
we describe a Chinese fossil from the Early Cretaceous 
period containing an embryo that is unambiguously a 
pterosaur. The embryonic skeleton, which is exquisitely 
preserved in its egg, is associated with eggshell 
fragments, wing membranes and skin imprints. This 
discovery confirms that pterosaurs were egg-layers and 
sheds new light on our understanding of pterosaur 
development.