The discovery of 92 nesting sites with a total of 256 fossilized dinosaur eggs is an incredible feat in and of itself. But, the nests and eggs are helping researchers better understand one of the largest dinosaurs that once roamed across India.
According to a recent study from the University of Delhi, India, published in PLOS One, a team of paleontologists uncovered the nesting sites in the Lameta Formation — an area of the Narmada Valley in central India and a hotbed for dinosaur fossils, especially from the Late Cretaceous Period. The eggs and nests belonged to one of the largest dinosaurs ever to live — the titanosaurs. This sauropod (long-neck herbivore) had a stockier frame and a wider stance than other typical sauropods.
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An Egg-celent Discovery in Fossils
Thanks to the recent findings, paleontologists can peer into the past and learn more about the nesting habits of the titanosaurs.
(Credit:Dhiman et al., 2023, PLOS ONE, CC-BY 4.0) (A) Completely unhatched egg from the clutch P43. (B) Almost fully intact circular outline of egg possibly indicating it to be unhatched and no loose eggshells are found in the clutch P6. (C) Compressed egg from clutch DR10 showing hatching window (arrow showing gap) and few eggshells collected just around the hatching window (circled) which possibly represent the remnants of hatching window. (D) Egg from clutch P26 showing curved outline. (E) Deformed egg from clutch P30 showing egg surfaces slipping past each other.
“Together with dinosaur nests from Jabalpur in the upper Narmada valley in the east and those from Balasinor in the west, the new nesting sites from Dhar District in Madhya Pradesh (Central India), covering an east-west stretch of about 1000 km (about 600 miles), constitute one of the largest dinosaur hatcheries in the world,” says co-author and research team leader Guntupalli V.R. Prasad, in a press release.
After analyzing the nests, the study authors identified six different species of titanosaur eggs — indicating that there may have been a wider diversity of titanosaurs in the area than previously thought — based on fossil records.
Modern-Day Relatives to Dinosaurs
According to the study, the nest layout indicates that the titanosaur may have laid its eggs in shallow pits, then buried them as modern-day crocodiles do. However, there was also evidence of the “egg-in-egg” phenomenon called counter-peristalsis contraction — a condition seen in chickens where the formed egg retracts into a hen’s oviduct only to have the second egg form around it then.
The nests also indicate that the titanosaur may have had a similar physiology to modern birds, where they sequentially laid their eggs. The close nesting proximity of these dinosaurs is similar to modern-day birds like great egrets, cormorants and brown pelicans.
The researchers also noted that due to the close proximity of the nests, the adult titanosaurs may have left the hatchlings to fend for themselves.
With these findings, researchers have gain valuable insights into these massive dinosaurs.
“Our research has revealed the presence of an extensive hatchery of titanosaur sauropod dinosaurs in the study area and offers new insights into the conditions of nest preservation and reproductive strategies of titanosaur sauropod dinosaurs just before they went extinct,” says Harsha Dhiman, lead author of the study in a press release.