Buried for 77 Million Years: Why Baby Dinosaur Fossils Are So Hard To Find

Juvenile dinosaur fossils are extremely rare. Fossils of dinosaurs this young — newly hatched, before they'd even had the chance to grow — are rarer still. These are two of them. Discovered in the Judith River Formation near Havre, Montana, these nestling dinosaurs are roughly 77 million years old, and almost impossibly intact: tiny vertebrae, femurs, even the small bumps on their eggshells are still visible, curled in the nest in the position in which they died. Normally, a baby dinosaur wouldn't survive long enough to fossilize at all — far more likely to be eaten by a larger predator than preserved. These two never had that chance. The evidence points to a sudden environmental event, likely a landslide, that buried the nest before any predator could reach it. Based on adult fossils found in the same layer, researchers believe these are likely lambeosaurs — duck-billed dinosaurs related to Maiasaura — though the exact genus and species are still to be confirmed. For researchers trying to understand how dinosaurs grew and developed, a find this complete, at this age, is the kind of specimen that's exceptionally hard to come by.