Ancient bird dinosaurs were so heavy they would have weighed around the same amount as a rhinoceros. Yet much like the chicken they laid eggs and sat on them, to provide protection and warmth, so how did these 3000-pound dinosaur birds do that without crushing the eggs into hundreds of little pieces?
If your first thought was, nope that cannot be possible, well you would have been wrong. They were able to do it, just needed to do this very very carefully. In fact, they had a whole ritual for sitting on their eggs and it used quite an ingenious method. These bird huge dinosaur called Oviraptorosaurs would place their oval eggs in a donut shape and then would shape their nest differently depending on their size.
What they would do is lay their eggs in a donut shape to keep a small hole in the middle, if they were very big they would even dig down into the hole. This allowed them to sit in the middle, tuck their legs in and keep all their eggs around them. Thus they adapted, to be able to sit on their eggs, protect them and not squash them. No birds today use this trick, however, even the largest birds of today are much smaller.
Oviraptorosaurs were very strange looking beasts with parrot faces and a toothless beak, and ranged from a few dozen pounds to over three thousand pounds! Over the years researchers have found many nests all perfectly ordered in donut shapes, it seems the birds were extremely picky about how they laid their eggs. If heat was the goal though, researchers noted this may not have been very optimal as they saw some nests the circle was so wide in diameter that the birds probably did not even touch the eggs.
Another phenomenon that shows that mother nature and wildlife always finds a way to adapt, no matter what difficulty they come across.