Overview
- A peer‑reviewed study published in early September 2026 confirms hundreds of titanosaur eggshell fragments from Argentina’s Chorrillo Formation represent the southernmost definitive dinosaur‑eggshell site.
- Field teams recovered the 255 fragments during expeditions in 2020 and 2024 from rocks that sat about 55–60° south in the Late Cretaceous, a cool temperate setting with average annual temperatures near 12°C.
- Scanning electron microscopy shows the shells are highly porous, which is a match for eggs buried in damp sand or piles of rotting vegetation where microbial heat and humidity would protect embryos.
- The eggs were small for adult titanosaurs at roughly 4 liters and hatchlings about 4 kilograms, which implies rapid, resource‑intensive growth after hatching and that the exact egg‑layer species remains unconfirmed despite colossosaurian teeth at the site.
- The find proves titanosaurs could reproduce in high‑latitude environments and now raises key questions for future research about whether these sauropods bred there year‑round or migrated seasonally and how nests and juvenile survival fit into their life history.