If you love dinosaurs as much as we do, at some point you have probably wondered about their eggs.
What shape were dinosaur eggs? How big were they? When were they first discovered? If you have been asking these types of questions, we’ve got some good news for you – because you’ve come to the right place. In this article, we’ll be sharing 10 ROARsome facts about dinosaur eggs.
Let’s dive in!
All dinosaurs hatched from an egg
This planet has been home to literally billions of dinosaurs. Billions. And every single one of those dinosaurs started life out by hatching from an egg.
The young of egg-laying animals do most of their growing and development outside of the mother’s body, which means she can conserve precious resources for egg laying and survival.
Females laid up to 20 eggs at a time
A “clutch” of eggs is the total number of eggs laid in a single sitting and some dinosaurs were able to lay clutches of as many as 20 eggs in one go!
As far as scientists can tell, clutch sizes would vary according to the species of dinosaur. Some dinosaurs may have only laid clutches of 1 to 5 eggs, while others laid as many as 15-20.
Almost 9 out of 10 dinosaur eggs never hatched
Palaeontologists estimate that only around 10% to 20% would have got the chance to hatch as the vast majority of dinosaur eggs would have been eaten by predators as soon as the mother left the clutch unattended.
Of the eggs that did hatch, many of the vulnerable hatchlings would also have been preyed upon by opportunistic carnivores looking for an easy lunch!
Dinosaur eggs are surprisingly rare
One of the reasons dinosaur eggs are so fascinating is because fossilised dinosaur eggs are actually incredibly rare. Finding a fossilised dinosaur egg or egg clutch is much rarer than finding a fossilised dinosaur skeleton. Eggs are much more fragile than bones and the prevalence of predators who ate them would have minimised their chances of being preserved.
Rarer still is finding a fossilised dinosaur egg complete with embryo. This is due, in part, to the fact that eggshells are porous and bacteria would be able to penetrate the shell and feast on the embryo within before it could be preserved. A very small number of preserved dinosaur embryos have been found and a fossilised Oviraptorosaurs embryo was discovered as recently as 2021 and it is the best example yet!
Dinosaur eggs were first discovered in 1859
It is documented that scientists theorised that dinosaurs laid eggs as far back as in 1820, but the first scientifically documented fossilised dinosaur eggs weren’t discovered until 1859. The 1859 discovery was made in France by Jean-Jacques Poech, although the eggs were assumed to have belonged to giant birds and weren’t classified as dinosaur eggs until much later.
The first scientifically recognised dinosaur eggs were discovered in Mongolia in 1923 by an expedition crew from the American Natural History Museum. These eggs belonged to the Oviraptor, which means Egg Thief.
Fragments of dinosaur egg shell are more commonly found
While it is still very rare to find fossilised dinosaur eggs or embryos, palaeontologists frequently uncover small fragments of dinosaur eggs at dig sites. These broken calcified fragments are often found among a variety of other fossils and are often ignored due to the far more valuable body fossils in the area.
Fossils of dinosaur eggs are what are known as “trace fossils”. Learn more about fossils and how they are formed.
Identifying the species that dinosaur eggs belong to is almost impossible!
Sometimes a fossilised dinosaur egg is found near the fossilised remains of the dinosaur who laid it but, if not, it is very difficult to identify which species of dinosaur the egg belongs to.
Dinosaur eggs are often broadly classified by their shape, size and texture and, although the specific species might be unidentified, scientists can often tell whether an egg was laid by a theropod, sauropod or other type of dinosaur.
The word for the allocation or classification of dinosaur eggs is “Oogenera”.
Some dinosaur eggs were round
While theropods (like Velociraptor and T-Rex) laid elongated eggs not dissimilar to the shape of modern day bird eggs, some dinosaur eggs were spherical.
In fact, these round eggs belonged to the beloved Sauropod classification of dinosaurs, which includes giants such as Brontosaurus, Diplodocus and Brachiosaurus. Nobody knows why these eggs were round or why the theropod eggs were elongated.
Dinosaur eggs could be up to 2 foot in diameter
Although we make new discoveries about dinosaurs all the time and there are still many things to learn about them, we know enough about their metabolism and reproduction to be able to confidently say that the biggest dinosaur eggs would have been around 2 foot in diameter.
While that is certainly pretty big by today’s standards (an ostrich egg, which is the biggest egg laid by birds that exist today, is less than a quarter of the size!), it pales in comparison to the size that actual dinosaurs could grow to be.
Sauropod hatchlings were smaller than you might think
Sauropod young were around the same size as a goose when they hatched. While adult Sauropods could grow to be as tall as 69 feet tall, they didn’t start out at that size from hatching – they just grew really really really fast!
Meet the dinosaurs at Paultons Park
Join us and celebrate your favourite dinosaur here with us at Paultons Park by spending a day visiting the Lost Kingdom. Lost Kingdom is a Jurassic themed prehistoric land full of dinosaur themed rides and attractions where you can even meet our “living” dinosaurs at ALIVE! Dinosaur encounter.
Book your tickets now to avoid disappointment on the day!!