Titanosaur Nests with 256 Fossilized Eggs Found in India Where Mother Dinosaurs Abandon Their Brood

Scientists discovered fossilized eggs in 256 Titanosaur nests in a long-gone river in India.

According to legend, the mother dinosaurs left their young behind.

Titanosaurs the size of school buses tromped through what is currently west-central India about 70 million years ago to lay their eggs by a riverbank.

Although the river and these long-necked sauropods are long gone, many of their nests are still standing and are filled with fossilized dinosaur eggs that can be used to learn more about how these enormous herbivores nested, laid their eggs, and whether or not they cared for their hatchlings.

Dinosaur Mothers Abandoning Their Brood

According to a new study the nests in the Indian state of Madhya Pradesh are so closely crowded together that it is also possible that titanosaur mothers abandoned their young soon after laying their eggs to avoid trampling their broods while navigating that cramped space.

The discovery of 92 nesting sites having a total of 256 eggs, likely laid by six titanosaur species, served as the basis for the findings, according to the study.

Michael D. D'Emic, an associate professor of biology at Adelphi University, said that In the upcoming years, there will be a sizable dataset to analyze due to the sheer volume of clutches and eggs.

S'Emic researches the evolution of dinosaurs but was not involved in the current study.

He sent an email to Live Science to communicate.

He pointed out that it is unknown how closely packed the "active" nests were because it is unclear whether the eggs were laid all at once or over a period of many years.

Six Species, Two Families

These titanosaur eggs were discovered by the authors through a series of field studies conducted between 2017 and 2020.

It came as a big surprise when they examined the fossils and found two families and six oospecies, or egg species.

Harsha Dhiman, a researcher in the Department of Geology at the University of Delhi, told Live Science in an email that three titanosaurid taxa are currently recognized from the Indian Cretaceous rocks.

Dhiman, the first author of the study published in the journal PLOS One, said that six oospecies are present, which suggested that there are still more titanosaur species to be found in the area.

Crocodile Traits and Egg-In-Egg Events

Among the remains, Dhiman and his colleagues also found a rare specimen of an ovum-in-ovo, or egg-in-egg, a condition that has only been documented in birds.

According to PhysOrg, this occurs when a ready-to-lay egg is pushed back into the body of the mother where it becomes embedded in a different, still-forming egg.

As egg-in-egg events have not been observed in other reptiles, it is possible that titanosaurs, which are living dinosaurs, had a reproductive system akin to that of modern birds.

However, not all of the titanosaurs' behavior was avian-like. The website made a suggestion that, like modern crocodiles, titanosaurs laid their eggs in a clutch and partially buried them, which aids incubation of the eggs through geothermal heat and solar radiation.

Archosaurs, a class of animals that also includes dinosaurs, pterosaurs, crocodilians, and birds, include crocodiles.

It is possible that some titanosaurs laid their eggs close to the water because it was simple to partially bury them in the soft, water-logged sediments, similar to how modern crocodiles prefer nesting habitats that are closer to water sources.

Darla Zelenitsky, an associate professor of dinosaur paleobiology at the University of Calgary in Canada, said that In a manner not too dissimilar from modern crocodiles, the researchers surmise that these dinosaurs were burrowing their eggs in nests close to lakes and rivers.

Zelenitsky was not involved with the study.

Hatchery Claim

Less is known about other nesting site specifics. Zelenitsky pointed out that it's unclear to the researchers whether multiple females simultaneously built the nests, as is the case in modern bird rookeries.

It is debatable whether a nesting site even existed.

The study more clearly identifies a location where numerous titanosaur eggs were laid over a short period of geologic time than it does the existence of a nesting site.

D'Emic said that, given the available data, the claim that the term "hatchery" refers to a colonial nesting area is a stretch.

These nests may have been built at intervals of decades, hundreds, or even thousands of years.

He added that although the discovery of a couple of hundred titanosaur eggs from a brief period is significant in and of itself, he does not believe that it is yet possible to prove that these nests existed at the same time.

Despite this, D'Emic and Zelenitsky are still enthusiastic about any potential fossil discoveries.

Zelenitsky told Live Science via email that it is truly astounding how many of these enormous dinosaurs' nests the researchers discovered-nearly 100.

This figure is most likely just the tip of the iceberg because many are still unidentified and concealed by rock, soil, or vegetation.

The fact that such significant discoveries are still being made is genuinely surprising, Live Science reported.