The object was found by Chilean scientists in 2011, but has only now been identified. It measures 28 by 18 centimeters and is the largest soft-shelled egg ever discovered.
In 2011, Chilean scientists discovered a mysterious fossil in Antarctica and took it to the Chilean National Museum of Natural History, where they tried to determine its age and what it was. These questions, however, have remained unanswered – until now.
One of the researchers, David Rubilar-Rogers, never gave up on the artifact: he showed it to all geologists who were visiting the museum. That’s how, in 2018, Professor Julia Clarke, from the University of Texas, in the United States, identified the fossil. “I showed it to her and, after a few minutes, Julia told me it could be a deflated egg,” said the researcher in a statement.
With this in mind, experts from both institutes decided to investigate the fossil in more detail and found that it dates from 66 million years ago. In an article published in Nature on Wednesday (17), the researchers reveal that the artifact measures 28 by 18 centimeters, is the largest soft-shelled egg ever discovered, and the second-largest egg of any known animal.
“It is from an animal the size of a large dinosaur, but it is completely unlike a dinosaur egg,” said Lucas Legendre, the study’s lead author. “It is most similar to the eggs of lizards and snakes, but it is from a truly giant relative of these animals.”
According to the researchers, the object is the first fossil egg found in Antarctica and, besides being enormous by conventional standards, it was probably laid by a reptile known as a mosasaur. The researchers deduced this after comparing the sizes of other species of reptiles with their eggs – and concluded that the animal should be approximately 6 meters long.
In addition, the rock formation where the egg was discovered is also home to several skeletons of mosasaurs and plesiosaurs. “Many authors have hypothesized that this was sort of a nursery site with shallow protected water, a cove environment where the young ones would have had a quiet setting to grow up,” said Legendre.