[ad_1]
A study of more than 250 fossil eggs found in India suggests long-necked titanosaurs nested in large groups, but left hatchlings to fend for themselves
Life
18 January 2023
A fossil dinosaur egg from the Lameta Formation in India Harsha Dhiman et al.
A treasure trove of fossil nests uncovered in India hints at an array of as-yet-undiscovered dinosaurs belonging to the titanosaur group, and gives clues to how these animals reproduced.
A total of 92 nests and 256 eggs, measuring up to 20 centimetres long, were found in the Lameta Formation, a sequence of rock layers well-known for containing fossils of immense, long-necked dinosaurs called titanosaurs. Palaeontologists had previously identified three titanosaur species from bones found in this area.
Guntupalli Prasad at the University of Delhi and his colleagues discovered the nests during fieldwork between 2017 and 2020. The team proposes that there are at least six egg shapes – technically called oospecies – found in the formation. If each egg shape was laid by a different species, it would double the known number of species in the formation.
Based on the layout of the nests, Prasad and his colleagues think the titanosaurs may have buried their eggs in shallow pits, as crocodiles do. They also suggest that they nested in colonies like many modern birds, but left the hatchlings to fend for themselves, as adult dinosaurs wouldn’t have had space to stay on the nests.
Darla Zelenitsky at the University of Calgary in Canada, who wasn’t involved with the study, urges caution on taking the six different egg types as a sign of six different species. Larger or smaller individuals of the same species might lay eggs that superficially seem different, or different species might lay eggs that are indistinguishable, she says.
Finding bones and eggs together will provide firmer evidence of how many dinosaur species were around, 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 in the heyday of the dinosaurs, this part of western India was a wet 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 would have made the area attractive to these dinosaurs.
These moist sediments also help explain why so many dinosaur nests came to be preserved in western India. When streams, marshes and ponds rose, nearby nests were inundated and buried.
More on these topics:
[ad_2]
Source link
