Scientists Discovered Thick-Shelled Turtle Egg with Embryonic Remains from Cretaceous Period
August 8, 2021
- Fossil record lacks specimens about turtle eggs containing embryos.
- Researchers provide the first description and taxonomy information of an egg with a preserved fossilized embryonic turtle.
- The fossil was discovered from the Upper Cretaceous Xiaguan Formation of Henan Province in China.
- The specimen is assigned to the Nanhsiungchelyidae which is an extinct group of large terrestrial turtles.
- The egg is one of the largest and thickest shelled turtle eggs from the Mesozoic Era.
- The egg is described as rigid and spherical.
- The new discovery allowed the identification of other Nanhsiungchelyid egg clutches and comparisons to those of Adocidae.
- Adocidae are extinct, omnivorous freshwater cryptodiran turtles and are mainly known from Cretaceous and Paleogene Asia and North America.
- Nanhsiungchelyidae and Adocidae form the basal extinct clade Adocusia of the Pan-Trionychia which consists of the living soft-shelled turtles.
- Nanhsiungchelyids had different habitats compared with adocids.
- However, Nanhsiungchelyidae and Adocidae shared some reproductive traits including thick eggshells, mid-size clutches, and large eggs.
- The unusual thickness of Nanhsiungchelyids eggshell may be associated with a nesting style adaptation to a very harsh environment.