At one point in what is now the Gobi desert, a group of dinosaurs bunkered down as a sand storm engulfed them. Now, 70 million years later, the fossilized remains of the three oviraptors has been uncovered, and scientists think that it might represent the first ever evidence that some dinosaur species roosted together, not unlike crows or bats do today.
The remains of the dinosaurs, which are thought to represent an as yet unnamed new species of oviraptorid, were almost lost to science. They were illegally poached from Mongolia, and only found by customs at the airport. It now seems that the bones may represent an incredibly significant dinosaur find: the first example of dinosaurs sleeping in a group.
The fossil consists of three individuals, although the partiality of one means that only two can be studied in any detail. They show that the dinosaurs were sat on their bellies, with their long necks curled back, and their heads cradled by their arms. This, says researcher Greg Funston, who is presenting his work at the Society of Vertebrate Paleontology meeting this week, is similar to how modern ostriches and emus bed down.
From the size of the leg bones of the unfortunate beasts, the scientists are able to estimate that at least two of them weighed roughly 45 kilograms (100 pounds) each. Fossils of adults show that oviraptors grew to around 75 kilograms (165 pounds), and another specimen thought to have been less than a year old tipped the scales at 33 kilograms (73 pounds).
The researchers have therefore estimated that these new ones were likely to have been between two and five years old. Not only that, but as female oviraptors are known to have laid eggs in large clutches, they also speculate that the dinosaurs may well have been siblings.
They say that the close configuration of the dinosaurs, in which they most likely would have been touching each other when alive, suggests that they may have been huddling together in order to keep warm, arguing that most modern animals that roost rarely make body contact for any other reason.
But others have cast doubt on this interpretation of the fossilized trio. Some researchers are instead suggesting that perhaps as the sandstorm that eventually buried them rolled in, the animals may have huddled together to sit it out. Or perhaps one of the dinosaurs had simply found a good spot to bed down for the night, and a couple of others wanted in on it.
Either way, regardless of which interpretation you prefer, the fossil is certainly raising some intriguing questions about the life and behavior of these animals as they stalked across what is now the Mongolian desert all those millions of years ago.