Largest clutch of ancient crocodile eggs discovered in Brazil

Find after decades

The fossil site of the Presidente Prudente Formation was discovered back in 2004. PThe deer seasons of 2021–2023 brought scientists three clutches: 15, 21 and 47 eggs. The latter is the largest clutch of Mesozoic crocodylomorphs ever found.

The analysis showed that the eggs have a characteristic ellipsoidal shape with blunt ends. The thickness of the shell varies from 0.3 to 0.8 mm, and its microstructure clearly indicates that it belongs to the group of crocodylomorphs.

Survival Strategy: Humidity and Care

Although scientists have not yet assigned the clutch to a specific species, the morphology of the shell provides important clues. The high porosity and significant thickness of the shell indicate that the eggs developed in a wet, swampy environment.

According to study leader Dr. Giovanna Paixan, this fecundity (47 eggs) brings ancient reptiles closer to modern crocodiles, which lay from 10 to 80 eggs. For comparison: most other known groups of notosuchians (suborder of extinct crocodylomorphs Southit hemisphereI melovoit periodA; led an exclusively land-based lifestyle) put off at that timewhether only 2–5 eggs and probably paying more attention to caring for the offspring.

Communal nesting sites of antiquity

The most exciting aspect of the discovery was the organization of the nesting site itself. The location of the masonry indicates that it waso colonial nesting site. UScientists suggest that different species of reptiles could use this territory at the same time.

“The spatial distribution of the nests hints at the existence of a large area where different species could interact,” explains Dr Paishan. “We are now analyzing nearby clutches belonging to other groups, including carnivorous therapod dinosaurs and ancient birds.”

All nests are located in the same stratigraphic layer, which confirms their synchronicity. This turns the Presidente Prudente into a unique Mesozoic “maternity ward”, where a variety of reptiles, from semi-aquatic crocodiles to feathered dinosaurs, bred side by side.