World’s Largest Dinosaur Eggs Discovered in China

A nesting gigantic cassowary-like dinosaur named Beibeilong is in the act of incubating its eggs. (Image:  Zhao Chuang   via    University of Calgary  )
A nesting gigantic cassowary-like dinosaur named Beibeilong is in the act of incubating its eggs. (Image: Zhao Chuang via University of Calgary )

The mystery of the world’s largest dinosaur eggs has been solved, and an infamous baby dinosaur fossil now has a family. The fossil dinosaur embryo “Baby Louie” and associated clutch of eggs were first discovered in the early 1990s, but were not formally described at the time.

In a paper published in Nature Communications, dinosaur paleontologist Darla Zelenitsky from the University of Calgary and co-authors identified the Baby Louie specimen as the embryo of a new species of oviraptorosaur, Beibeilong sinensis, that lived in central-eastern China 90 million years ago during the Late Cretaceous period.

Baby Louie fossil would have grown to gigantic dinosaur

The Baby Louie fossil was discovered in 1993 in a rock formation from the western part of China’s Henan Province. At that time, tens of thousands of dinosaur eggs were being collected by local farmers, then sold and exported to other countries. Many, like Baby Louie, ended up in the United States where it was eventually sold to the Indianapolis Children’s Museum in 2001.

Zelenitsky and her co-authors Philip Currie and Kenneth Carpenter first began examining Baby Louie (a nickname given by Charlie Magovern, who first exposed the fossil after it came to the United States) shortly after it arrived in the United States.

They noticed the eggs and embryo skeleton looked similar to those of oviraptorosaurs, a group of meat-eating dinosaurs that superficially look like cassowaries, but the eggs were far too large to have been laid by any known species of such dinosaurs at the time.

Right image shows schematic overlay of approximate locations of individual eggs. Eggs 1 through 4 are in an upper layer just beneath the skeleton, whereas Egg 5 is in a lower layer of the block. Scale bar is in centimetre.

Right image shows schematic overlay of approximate locations of individual eggs. Eggs 1 through 4 are in an upper layer just beneath the skeleton, whereas egg 5 is in a lower layer of the block. Scale bar is in centimeters. (Image: Nature Communications )

Zelenitsky, who is an assistant professor in the Department of Geoscience, said in a statement:

Along with the dinosaur embryo, the Baby Louie fossil contains between six and eight very large eggs. These giant eggs were given their own scientific name, Macroelongatoolithus (meaning large elongate stone eggs).

(a) Photograph. (b) Highly schematic outline shows general layout of the skeleton (illustrated by Zhaochuang). Scale bar, 5 cm. d, dentary; f, femur; fi, fibula; fr, frontal; lj, lower jaw; or, orbit; ti, tibia.

(a) Photograph. (b) Highly schematic outline shows general layout of the skeleton (illustrated by Zhaochuang). Scale bar, 1.9 inches (5 cm). d, dentary; f, femur; fi, fibula; fr, frontal; lj, lower jaw; or, orbit; ti, tibia. (Image: Nature Communications )

These are the largest-known type of dinosaur eggs, with eggs reaching up to 23 inches (60 cm) in length (the eggs associated with Baby Louie reach about 17 inches (45 cm) long) that are laid in ring-shaped clutches two to three meters in diameter and contain two dozen or more eggs. The Baby Louie specimen was likely part of one of these large ring-shaped nests.

Eggshell fossil held key to identifying new species

In 2007, a completely unrelated discovery turned up a solution to the mystery behind Baby Louie’s lineage — the first known giant oviraptorosaur, with an estimated body length of 26 feet (eight meters), was unearthed in northern China. At long last, oviraptorosaurs large enough to have been capable of laying eggs as large as Baby Louie’s were known to have existed.

The drawing shows the approximate size of the Beibeilong embryo inside a Macroelongatoolithus egg (drawn by Vladimir Rimbala).

This drawing shows the approximate size of the Beibeilong embryo inside a Macroelongatoolithus egg (drawn by Vladimir Rimbala). (Image: Nature Communications)

In their article, Zelenitsky and her co-authors compared the bones, and discovered that the Baby Louie skeleton belongs to a different kind of giant oviraptorosaur and have given it a brand-new dinosaur name: Beibeilong sinensis, meaning “baby dragon from China.” Zelenitsky explained, saying:

Ring-shaped nests of eggs of smaller oviraptorosaur species have been found with the adults sitting in the center of the nest, so an adult Beibeilong probably shared similar behaviors.

With their parrot-like skulls, feathers, and two-legged stance, Baby Louie’s parents, weighing in at around 6,613 pounds (3,000 kilograms) — about half as heavy as a Tyrannosaurus Rex — are the largest dinosaurs likely to have sat on their nests to brood their clutch of eggs.

Now that the true identity of the Macroelongatoolithus eggs has been resolved, paleontologists can try to determine the geographic distribution of giant oviraptorosaurs. Zelenitsky went on to say:

In 2013, Baby Louie was repatriated to the Henan Geological Museum in its home province.

This article was written by Erin Guiltenane of the  University of Calgary

[Note: Materials may be edited for content and length.]

Like this article? Subscribe to our weekly email for more! 

NASA Rover Samples Active Linear Dune on Mars