Treasure trove of fossil eggs hints titanosaurs nested in colonies

A examine of greater than 250 fossil eggs present in India suggests long-necked titanosaurs nested in massive teams, however left hatchlings to fend for themselves

By Riley Black

A treasure trove of fossil nests uncovered in India hints at an array of as-yet-undiscovered dinosaurs belonging to the titanosaur group, and provides clues to how these animals reproduced.

A complete of 92 nests and 256 eggs, measuring as much as 20 centimetres lengthy, had been discovered within the Lameta Formation, a sequence of rock layers well-known for holding fossils of immense, long-necked dinosaurs referred to as titanosaurs. Palaeontologists had beforehand recognized three titanosaur species from bones discovered on this space.

Guntupalli Prasad on the University of Delhi and his colleagues found the nests throughout fieldwork between 2017 and 2020. The workforce proposes that there are no less than six egg shapes – technically referred to as oospecies – discovered within the formation. If every egg form was laid by a distinct species, it might double the recognized variety of species within the formation.

Based on the structure of the nests, Prasad and his colleagues suppose the titanosaurs could have buried their eggs in shallow pits, as crocodiles do. They additionally recommend that they nested in colonies like many fashionable birds, however left the hatchlings to fend for themselves, as grownup dinosaurs wouldn’t have had area to remain on the nests.

Darla Zelenitsky on the University of Calgary in Canada, who wasn’t concerned with the examine, urges warning on taking the six completely different egg varieties as an indication of six completely different species. Larger or smaller people of the identical species would possibly lay eggs that superficially appear completely different, or completely different species would possibly lay eggs which might be indistinguishable, she says.

Finding bones and eggs collectively will present firmer proof of what number of dinosaur species had been round, says Zelenitsky. “That said, there is clearly something interesting about the Lameta Formation to consistently produce a number of different titanosaur egg types,” she says.

Back within the heyday of the dinosaurs, this a part of western India was a moist and marshy lowland dotted with small lakes. “The flats offered sites close to water sources, soft soil for nest burial and possible availability of food for juveniles,” says Prasad, all of which might have made the realm enticing to those dinosaurs.

These moist sediments additionally assist clarify why so many dinosaur nests got here to be preserved in western India. When streams, marshes and ponds rose, close by nests had been inundated and buried.