In 2011, researchers from Chile discovered a mysterious fossil in the shape of a deflated rugby ball in Antarctica. The object has sat in Chile’s National Museum of Natural History for almost a decade, with scientists unable to determine its origin. The rock-like object was so baffling, scientists simply referred to it as “The Thing”.
However, experts at the University of Texas at Austin have analysed the fossil, and discovered it is a giant, soft-shell egg from about 66 million years ago.
At 11 inches by 7 inches, it is the largest soft-shell egg to ever be discovered, and the first fossilised egg to be discovered in Antarctica.
The soft-shell egg did not come from dinosaurs, but rather a giant reptile, according to the research published in the journal Nature.
Lead author Lucas Legendre, a postdoctoral researcher at UT Austin’s Jackson School of Geosciences, said: “It is from an animal the size of a large dinosaur, but it is completely unlike a dinosaur egg.
“It is most similar to the eggs of lizards and snakes, but it is from a truly giant relative of these animals.”
The shell had deflated as whatever was inside it had hatched 66 million years ago.
But by comparing the shell to 259 living reptile eggs, Mr Legendre found a correlation between reptile size and its eggs.
By doing so, the reptile which laid the ancient egg would have had to be more than 20 feet long from the tip of its snout to the end of its body, not counting a tail.
“The other involves the reptile depositing the eggs on a beach and hatchlings scuttling into the ocean like baby sea turtles.”
The researchers say this would demand some fancy maneuvering by the mother because giant marine reptiles were too heavy to support their body weight on land.
“Laying the eggs would require the reptile to wriggle its tail on shore while staying mostly submerged, and supported, by water.”