A 90-million-year-old egg was found

Researchers re-examined a huge egg that they initially thought belonged to a dinosaur, and determined that it was in fact belonging to a giant tortoise that was five feet long (one and a half meters) and had a fossilized embryo inside.

The newspaper "Daily Mail" reported that the semi-spherical egg the size of a tennis ball, which measures 2.1 x 2.3 inches, was discovered in Henan Province, China, and belongs to the group of turtles "Nanhsingchlidai" and "Nanyangansis" species.

This now-extinct turtle flourished during the Upper Cretaceous period, approximately 90 million years ago.

However, all of these turtles died around the time the dinosaurs became extinct, according to reports.

Experts believe that the egg's thick shell allowed water to pass through, so it was buried deep in the ground and did not dry out, allowing the embryo to survive all these years.

"Spherical eggs can also reduce water loss, and the dense eggshell in some reptiles may be an adaptation to the dry climate," the researchers wrote in the study.

They said: "The egg is spherical with a thick shell (about 0.7 - 1.0 mm) of this species of turtle, as it is also suggested that it has adapted to arid environments."

Darla Zelenitsky, one of the study's co-authors, told CBC that the egg was found near ancient rivers, which may help preserve it when it overflowed.

"During the rainy season, these rivers may have overflowed and buried the egg that was in the floodplain, potentially preserving them as fossils," Zelenitsky added.