Rare egg fossils reveal dinosaurs weren't doting parents - CNN

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Paleontologists moving successful central India person made a uncommon find — a fossilized dinosaur hatchery with 92 nests and 256 eggs belonging to colonies of elephantine plant-eating titanosaurs.

A survey of the nests and their bowling ball-size eggs has revealed intimate details astir the lives of the colossal, long-necked sauropods that lumbered crossed what’s present cardinal India much than 66 cardinal years ago.

The eggs, which ranged betwixt 15 centimeters and 17 centimeters (6 inches and 6.7 inches) successful diameter, apt belonged to a fig of titanosaur species. The fig of eggs successful each nest ranged from 1 to 20, said pb survey writer Guntupalli Prasad, a paleontologist successful the section of geology astatine the University of Delhi. Many of the nests were recovered adjacent together.

The findings suggested titanosaurs, among the largest dinosaurs to person lived, were not ever the astir attentive parents, Prasad said.

“Since titanosaurs were immense successful size, intimately spaced nests would not person allowed them to sojourn the nests to maneuver and incubate the eggs oregon provender the hatchlings … arsenic the parents would measurement connected the eggs and trample them.”

Finding a precise ample fig of dinosaur nests is unusual, arsenic preservation conditions person to beryllium “just so” to person turned each the delicate eggs to fossils, said Dr. Darla Zelenitsky, an subordinate prof of dinosaur paleobiology astatine the University of Calgary successful Canada, who studies dinosaur eggs. Zelenitsky was not progressive successful the research.

The archetypal dinosaur eggs successful the portion were discovered successful the 1990s, but the latest survey focused connected a nesting tract successful Dhar district in the authorities of Madhya Pradesh, wherever excavations and fieldwork took spot successful 2017, 2018 and 2020.

The eggs discovered determination were truthful good preserved that the squad was capable to detect degraded macromolecule fragments from the eggshells.

Titanosaurs’ nesting behaviors shared characteristics with that of today’s birds and crocodiles, the probe suggested.

From the adjacent proximity of the nests, researchers inferred the dinosaurs laid eggs unneurotic successful colonies oregon rookeries, arsenic galore birds bash successful the contiguous day.

“Such nesting colonies would person been a show to spot backmost successful the Cretaceous wherever the scenery would person been dotted by a immense fig of ample dinosaur nests,” Zelenitsky said.

Prasad said one peculiar ovum — known arsenic an ovum-in-ovo, oregon egg-in-egg — the squad had studied showed birdlike reproductive behaviour and indicated that, akin to birds, immoderate dinosaurs whitethorn person laid eggs sequentially. Ovum-in-ovo forms hap successful birds erstwhile an ovum becomes embedded successful different ovum inactive successful the process of forming earlier they are laid.

“Sequential laying is the merchandise of eggs 1 by 1 with immoderate clip spread successful betwixt 2 laying events. This is seen successful birds. Modern reptiles, for illustration turtles and crocodiles, connected the different hand, laic each eggs unneurotic arsenic a clutch,” helium said.

The eggs would person been laid successful marshy flatlands and buried successful shallow pits, akin to the nesting sites of modern-day crocodiles, Prasad said. Similar to crocodile hatcheries, nesting adjacent to h2o whitethorn person been important to forestall the eggs from drying retired and offspring dying anterior to hatching, Zelenitsky added.

But dissimilar birds and crocodiles, which some incubate their eggs, Prasad said that, based connected the carnal characteristics of the nests, titanosaurs apt laid their eggs and past near the babe dinos to fend for themselves — though much information is needed to beryllium sure.

Other dinosaurs were thought to beryllium much attentive parents. A dinosaur was discovered successful Mongolia successful the 1920s, for example, lying adjacent a nest of eggs thought to beryllium to a rival. Paleontologists astatine the clip assumed the carnal had died portion attempting to plunder the nest — and named the carnal oviraptor, oregon “egg thief.”

The alleged dinosaur thief’s estimation wasn’t restored until the 1990s, erstwhile another find revealed the eggs were, in fact, its own and that the carnal apt sat upon them successful a neatly arranged nest.