66 million-year-old egg the size of a football discovered in Antarctica

Chilean scientists have come across a “football-sized egg” in Antarctica which is believed to be around 66 million years old. The egg is described as being deflated and more than 28-by-18-centimetres long, and it’s thought to have been laid by an ancient marine reptile called a mosasaur.

The egg is the largest soft-shell egg ever discovered and the first to have been found in Antarctica. It has been studied closely by scientists for over a decade and the findings are incredible.

A giant egg dating back 66 million years has been discovered, thought to have been laid by an extinct marine reptile measuring six metres long.

Scientists have thoroughly studied the egg in the ten years that have passed since it was first recovered. Having hatched tens of millions of years ago, the exterior of the shell has “visibly collapsed and folded”, leaving a shell that is amongst one of the largest ever discovered – second only to the eggs of Madagascar’s giant extinct elephant birds.

“It is from an animal the size of a large dinosaur, but it is completely unlike a dinosaur egg,” described study author Lucas Legendre, a researcher from the University of Texas Austin’s Jackson School of Geosciences. “It is most similar to the eggs of lizards and snakes, but it is from a truly giant relative of these animals.” 

As nothing like this has ever been discovered, it was previously thought that such giant marine reptiles did not lay eggs.

The giant fossil egg.

Most interestingly, the egg has given researchers further insight into the animal from which it came – particularly how it would have behaved throughout reproduction and birth. For example, the area where the egg was discovered also has remnant fossils of baby and adult mosasaurs and plesiosaurs, suggesting that the surrounding rock formation may have served as a “nursery site.”

An artistic depiction of what the mosasaur may have looked like. Artwork by Francisco Hueichaleo.

Interesting stuff, if you would like to check out the full report and findings, head here for more information.