Guide to Dinosaur Eggs: 5 Things to Know About How Dinosaurs Hatch
Which came first, the dinosaur or the egg? Practically every dinosaur that lived during the Mesozoic Era hatched from an egg, much like birds and reptiles do today. All of Jurassic World's biggest stars are born in this way—from the Tyrannosaurus rex to the Dilophosaurus—making research into eggs and how they hatch a major part of Jurassic World scientists' daily work.
Here are some key facts about how dinosaurs hatch:
So many eggs...so few dinosaurs
Scientists know that dinosaurs laid eggs in the same way reptiles and birds do today and that they laid their eggs in clusters. Some dinosaurs laid as many as 21 eggs in a single nest to increase the chances that at least one baby would survive an attack by a predator.
However, Jurassic World's Mosasaurus lived their whole life in the water and gave birth to live offspring, the same as modern-day whales. As a result, baby Mosasaurus need to be able to swim right from the moment they're born.
Bonding with the baby dinosaurs
Some species would even stay to care for their young once they hatched. Velociraptors are thought to have looked after and fed their offspring until they could find food on their own.
At Jurassic World's Hammond Creation Lab, the staff carefully watches all the eggs until they're ready for the nursery. After hatching, the dinosaurs receive care from our dinosaur behaviorists, reflecting John Hammond's belief in the power of bonding.
Raptor trainer Owen Grady raised Blue from the day she hatched, learning her body language just as she learned his. Once they're big enough, the dinosaurs head over to their own attractions.
Size doesn't matter with dinosaur eggs
Dinosaurs eggs came in all shapes and sizes. Paleontologists believe no dinosaur egg could ever have spanned more than two feet in diameter—and most were closer in size to a tennis ball. But egg size didn't necessarily determine how big a dinosaur would grow—the Diplodocus laid eggs about the same size as an ostrich, despite being far bigger in size. Even Jurassic World's 50-foot-tall Indominus rex didn't lay particularly large eggs.
While many dinosaurs laid round eggs, meat-eating dinosaurs produced eggs that were usually much longer than they were wide. These may have been less likely to roll away, helping to stop other dinosaurs from making them their lunch.
The big reveal can take a while
We don't know exactly how long each species of dinosaur would take before they hatched. Birds would likely have laid eggs that could hatch in a few weeks, while most dinosaurs would probably have produced eggs that hatched in three to six months. As for the biggest species, their eggs may have taken up to a year to hatch.
At Jurassic World, two to five dinosaurs are born each week. Tourists can visit the lab and see the scientists at work, and can even get a glimpse of newly-hatched versions of the raptor, the T. rex and other dinosaurs in the nursery.
Is that a rock or a dinosaur egg?
As much as we all would love to think our backyard could yield its own Jurassic World, finding a dinosaur egg is unfortunately quite rare. So don't go digging up the rose bushes quite yet!
If you do find something that looks like a dinosaur egg, chances are it's a round stone or even an old bird egg. But if you're convinced it's the real deal, you can always take it to a local museum, or better you bring it over to one of the scientists at our Innovation Lab—we'd be happy to take a look!