Titanosaurus egg found in India with another egg inside
Miscellaneous / / June 23, 2022
This "matryoshka" confirms that dinosaurs are closer to modern birds than to reptiles.
Paleontologists foundFirst ovum-in-ovo pathological titanosaurid egg throws light on the reproductive biology of sauropod dinosaurs / Scientific Reports in India, a fossilized egg in another titanosaur egg is also called ovum-in-ovo (literally "egg-in-egg"). Similar abnormalities at the embryonic stage of development sometimes occur in the eggs of modern chickens, but this is the first find with such a pathology, 68 million years old.
Ovum-in-ovo is one of two important pathologies that help understand the reproductive characteristics of birds and reptiles. In modern birds, it manifests itself in the appearance of a second layer of shell inside the egg. Between these layers there is a gap occupied by the yolk. The second pathology is several layers of the shell on one egg, located close to each other. They can be separated by an organic membrane, but in this case there is no second yolk.
Previously, scientists have found eggs with multiple layers of shells in turtles, dinosaurs, crocodiles, lizards, several modern bird species, and the fossil enanciornithine bird. But ovum-in-ovo was previously considered a pathology of archosaurs - birds and crocodiles.
The situation was changed by a fossil egg measuring 16.6 × 14.7 cm, found in a dinosaur nest in the geological formation of Lamet (India). The find belongs to the Upper Cretaceous and consists of two layers of shell with fragments between them.
This arrangement of an egg inside another egg, with a significant gap between the two layers of the shell, is very similar to ovum-in-ovo. in modern birds, on the basis of which scientists concluded that this is the first documented example of ovum-in-ovo in dinosaurs.
This confirms that the reproductive biology of titanosaurs and other sauropod dinosaurs is more similar to crocodiles and birds than to non-archosaurian reptiles.
Read also🧐
- Paleontologists have discovered a new species of giant dinosaurs
- In China, found an egg with a perfectly preserved dinosaur embryo