Rare embryo found inside prehistoric turtle egg

An illustration of the prehistoric nanhsiungchelyid turtle hatched from its egg. (Masato Hattori)

Henan Province in central China is a treasure trove of dinosaur eggs. However, the strange black orb with a blue tint, presented to Fenglu Han and Haishui Jiang by a farmer in 2018, did not look like any dinosaur egg that experts had meet before. The paleontologists of the University of Geosciences of China initially thought that the egg might belong to a new species of prehistoric giants.

However, a closer exam revealed that the size of a tennis ball fossil housed a well-preserved embryo of a faded away prehistoric turtle called nanhsiungchelyid. The massive land animals roamed North America and Asia during the Cretaceous period – from 145 to 66 million years ago.

This is the first time that researchers have been able to identify the turtle species from an embryo. (Yuzheng Ke)

The discovery is extremely exciting given that intact turtle eggs from the Cretaceous period are hard to find. They are usually too small and too brittle to survive. The few fossil embryos found in the past were not well enough preserved to identify turtle species.

“It is in fact the first time that [fossil] turtle eggs or a nest could really be attributed one turtle in particular, ”said Darla Zelenitsky, study co-author and University of Calgary paleontologist. Radio-Canada.

A CT image of the embryonic bones inside the turtle egg (Courtesy Ke.et.al. 2021)

Scientists believe recently discovered turtle egg managed to stay unharmed for 90 million years due to its large size and robust shell. Measuring 2.1 by 2.3 inches (5.4 by 5.9 centimeters), it is just a a little smaller than the eggs laid by the massive Galapagos tortoises. Its 0.07 inch thick (1.8 mm) shell – about four times thicker than that of Galapagos turtle eggs – was capable of resist outside forces and help keep much needed water. As part of the shell is broken, Zelenitsky wonders if the turtle failed in its attempt to hatch.

Based on the size of the egg, the researchers estimate that parents shell was a staggering 5.3 feet (1.6 meters) in length. Add the length of the neck or head, and the massive the animal was probably as big as an average human!

A nanhsiungchelyid turtle fossil found in Alberta, Canada (Royal Tyrell Museum)

The team, who published their findings in the journal Proceedings of the Royal Society B August 18, 2021, theorize that the species is gone faded away when the weather has changed. Zelenitsky said: “Although the unique earthly way of life, thick and underground eggs nesting strategy served them well during the Cretaceous Period, it is possible that these specialized the turtles could not adapt to the cooler climate and environmental changes according to the final Cretaceous mass extinction. “

Resources: Livescience.com, Nationalgeographic.com