Dinosaurs who stuck together, survived together

During the early Jurassic Period, some 200 million years ago, the only large herbivores in many ecosystems were long-necked dinosaurs called sauropodomorphs. These reptiles were the forerunners of the gargantuan sauropods, the group that included Brachiosaurus and Brontosaurus.

A well-populated breeding ground in southern Patagonia hints at one reason early sauropodomorphs were so successful: They knew how to stick together. When scientists analyzed the eggs and skeletal remains of juveniles and adults of a species known as Mussaurus patagonicus, they found that the fossils…