Humans are far from the only species to dote on their offspring. It can’t be denied, however, that the wilds of Earth are neither kind nor forgiving. And in the time of dinosaurs, the animal kingdom was perhaps even more savage. In a recent PLOS study of dinosaur egg fossils, researchers revealed just how callous dino parents could be.
It began with a rare discovery. Near the mighty Narmada River in India, paleontologists unearthed a fossilized dinosaur hatchery containing 92 nests and 256 eggs once belonging to colonies of colossal titanosaurs. While studying the bowling ball-sized eggs, scientists came to the conclusion that the species weren’t exactly the most caring parents.
“Since titanosaurs were huge in size, closely spaced nests would not have allowed them to visit the nests,” explained paleontologist and lead study author Guntupalli Prasad. Because of this, the dinosaurs couldn’t incubate their eggs or feed their hatchlings. If the dino parents tried, they “would step on the eggs and trample them.”
Researchers found the eggs, which measured over 6 inches in diameter, in tightly grouped nests, each one containing one to 20 hatchlings. Given the titanosaur’s size, it’s a wonder that their eggs weren’t even larger. Experts believe the towering herbivore is one of the largest (if not the largest) dinosaurs to ever walk the earth.
Though egg fossils aren’t a new discovery, this hatchery was particularly interesting. Finding such a large number of preserved nests is highly unusual, as dino eggs require the perfect conditions to fossilize.
To make these eggs even more fascinating, they were astoundingly well preserved. So much so, in fact, that scientists were able to detect degraded protein fragments from the shells.
Egg Fossils Reveal Dinosaurs’ Nesting Habits
Through the research of the dinosaur egg fossils, scientists found more than poor parenting. They also found clues suggesting titanosaurs’ nesting behavior isn’t so foreign, after all. The dinosaurs’ approach to laying eggs closely resembled that of today’s birds and crocodiles.
Due to the closeness of the nests, scientists believe titanosaurs laid eggs in colonies or rookeries, just like present-day birds. “Such nesting colonies would have been a sight to see back in the Cretaceous. The landscape would have been dotted by a huge number of large dinosaur nests,” explained dino egg expert Dr. Darla Zelenitsky.
Additionally, scientists found the first example of an egg-in-egg dinosaur egg. Also known as ovum-in-ovo, this phenomenon occurs in birds when one egg becomes embedded in another before they’re laid.
“Sequential laying is the release of eggs one by one with some time gap in between two laying events. This is seen in birds. Modern reptiles – for example, turtles and crocodiles – on the other hand, lay all eggs together as a clutch,” he said.
According to researchers, the location of the egg fossils indicated that mama dinos laid them in marshy flatlands and buried them in shallow pits – much like crocodiles of today. And like crocodiles, nesting close to water likely stopped the eggs from drying out, thus preventing the offspring from dying prior to hatching.