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| credit:G. Funston |
Dinosaurs are still with us, the archetypal survivors. Small feathered dinosaurs survived the apocalypse of asteroid impact and catastrophic climate change. We should be so lucky. More fossil evidence of the evolutionary connection between modern bird species and dinosaurs has come to light in central Asia, where Mongolian custom seized a very unusual fossil specimen in 2006. [photo]. A vertebrate paleontologist, Fredrico Fanti, at the University of Bologna placed the age of the fossil at 70 million years, and its location in the Gobi Desert, probably the Goblin Tsav site.
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| credit:M Skrepnick |
What makes this seemingly indecipherable jumble of bones special is it represents the first fossil evidence of dinosaurs roosting together like modern birds.
[color diagram above] Birds and bats roost in groups to regulate their body temperature while they sleep. These three oviraptorids from the Cretaceous were young, sleeping close together, perhaps for warmth when they perished. Two of the dinosaurs, more complete than the third, are in a crouched
position with their bellies on the ground and their necks extended over
their back. This position is similar to the pose of ostriches and emus
when they are in deep sleep. These are a new species of oviraptorids, which walked upright on two legs and had a crest on their head similar to the cassowary.
[artist's impression] According to the size of the thigh bone they weighed about 45 kg each. A handful of previous fossil finds catch dinosaurs sleeping when they died, but this fossil is the first to capture a group roosting, suggesting a complex social life. The trio “clearly had a quite close bond”, since they died touching, a researcher says. Oviraptorids browsed for food in groups and probably flashed their crests at rivals or
potential mates.
