A 150-million-year-old clutch of fossilized dinosaur eggs is providing scientists with new evidence of how eggs evolved. The eggs were laid by a dinosaur belonging to a group of species called theropods. Tyrannosaurus rex, as well as today’s birds, belong to this group. Most of the time, scientists can’t tell what kind of dinosaur laid the eggs they find, but the fossil embryos inside the eggs were developed enough for scientists to tell which group of dinosaurs they were from.
Scientists discovered that the eggs had fewer layers than eggs from later dinosaurs and birds. They also know that the eggs were buried to incubate, because of the amount of pores in the eggshell.
