Table of contents
90 million years ago, in the Age of Dinosaurs, there lived a giant tortoise ( Yuchelys nanyangensis) One of their pool-ball-sized eggs, with an extremely thick shell, did not hatch and has been preserved to this day.
The fossil was found in 2018 by a farmer in Honan province, a place known for having many dinosaur egg fossils.
So the farmer donated the fossilized egg to two scientists at the University of China, who are now publishing their findings in a new paper.

The fossil of the giant tortoise egg. Image: Yuzheng Ke
Egg fossil brings important new discoveries
Turtle egg fossils are quite rare, so the study of the fossilized embryo brought new perspectives on how the giant turtle species that went extinct along with the dinosaurs lived.
The eggshell of the species Yuchelys nanyangensis is very thick and measures about 5.9 cm, being larger than eggs of living Galapagos tortoises! This feature allowed water passage and protection, so the eggs could be buried deeper. This made them avoid the arid climate of the time.
From the size of the fossil, scientists made a calculation to estimate the length of the shell of the egg-laying turtle. The turtle measured about 1.6 meters, not taking into account the neck and head, just the shell. Thus, it is one of the largest of the species ever studied by scientists!

The carapace of the studied giant tortoise found in China. Image: Don Brinkman)
Fossilized embryo
If turtle egg fossils are rare to find, embryos are even more so. The animal's tissues and bones are easy to break down over the years.
Thus, scientists tried to study as much as they could of this embryo.
To do this, they took a CT scan to analyze the inside of the fossil.
The 3D images from the CT scan revealed small disarticulated bones inside the egg, so by reconstructing the bones in a program, the scientists concluded that the embryo was 85% formed.
Many conclusions came from just one small egg fossil from the Age of Dinosaurs. This discovery brings new energy for scientists to discover more fossils in the region and be able to put together all the puzzles of these ancient turtles.
- Eating only half an egg with yolk a day may increase the risk of death
- Egg found in Antarctica may be from mysterious giant creature
- Archaeologists discover 1,000-year-old egg in Israel and accidentally break it
- Child discovers dinosaur eggs of 66 million years alone
- Yellow turtle is found in India; see this unusual phenomenon