A pelvis can say so much


It's an impressive piece of detective work to take a fragment of a fossil and learn something about the behavior of dinosaurs. This is a fossil that consists of only the pelvic region of an oviraptor, which also happens to have a pair of large eggs nestled inside it. This poor female was pregnant at the time of her death, and was just about ready to lay these eggs.

It doesn't sound like much, but here's what we learn from it:

  • -Oviraptors had two functional oviducts, like modern crocodiles. They laid their eggs in pairs.
  • -These are large eggs, and the animal didn't have a lot of room in there—so it only laid a few at a time. It wasn't like modern sea turtles, dumping a load of eggs in a nest all at once.
  • -Oviraptor nests have been found, and they contain many eggs. This had to have been done by repeated visits and multiple egg-laying sessions, suggesting a fair amount of parental investment in the nest.
  • -The pointed end of the egg is pointed caudally. In oviraptor nests, the eggs are all in circular rings, with the pointed end outward. From this we can infer that the mother oviraptor stood in the center of the nest when laying the eggs.

Isn't it cool where a little evidence and logic will take you?

(See a larger image on Pharyngula)