A unique fossilised dinosaur egg discovered in Madhya Pradesh of India has been making news. The set of eggs was discovered by a team of researchers from Delhi University, with one nesting within another.
The discovery was made in Dinosaur Fossil National Park in Madhya Pradesh's Dhar district and the eggs belong to titanosaurs, a diverse group of sauropod dinosaurs.
This is the first time that scientists have come across the rare phenomenon of eggs-within-eggs within dinosaurs. It is known to occur only in birds but never in reptiles.
"The discovery of ovum-in-ovo egg from a titanosaurid dinosaur nest suggests that their oviduct morphology was similar to that of birds opening up the possibility for sequential laying of eggs in this group of sauropod dinosaurs. This new find underscores that the ovum-in-ovo pathology is not unique to birds and sauropods share a reproductive behavior very similar to that of other archosaurs," said the research published in the journal.
The Upper Cretaceous Lameta Formation of Central India is long known for its dinosaur fossils. The team of the scientists found 52 nests of titanosauris sauropod near the national park in which one of the nests contained 10 eggs. The "abnormal or pathological" egg was found among them.
"The abnormalities reflected in the eggshells include multiple eggshell units occurring in close contact with each other and one above the other (multi-shelled), abnormally thick or thin eggshells, abnormally shaped shell units, extra shell units blocking pore canals, and surface defects," said the research.
The discovery offers further insights into the connection between the dinosaurs and reptiles, the diversity within the dinosaurs, their nesting behaviour and dinosaur reproduction.