Sauropod babies as main prey

A new study shows that baby sauropods, like those of Diplodocus or Brachiosaurus, were the primary food source for carnivorous dinosaurs during the Jurassic period. This finding challenges previous assumptions about dinosaur diets and predator-prey dynamics.

Sauropods did not care for young

Unlike modern marine turtles, which lay many eggs and then abandon them, sauropods also did not nurture their young, according to Cassius Morrison, a paleoecologist at University College London. This lack of parental care left their offspring vulnerable to predators.

Fossils reveal predator choices

Researchers analyzed fossils from the Dry Mesa quarry in Colorado, an exceptional site from the Upper Jurassic. They found that predators like Allosaurus had a choice between attacking heavily armored herbivores like Stegosaurus or targeting thousands of young sauropods with soft skin.

Energy efficiency shaped hunting

The study suggests that attacking baby sauropods was more energy-efficient for predators. Stegosaurus, for example, posed a risk of injury due to its armor, while baby sauropods were easier to catch and less dangerous to attack.

Evolution of dinosaur weapons

The abundance of easy prey may have slowed the evolution of powerful weapons among Jurassic predators. Allosaurus, for example, was a strong hunter but did not have the powerful bite of later carnivores, as it did not need to evolve such traits when easy food was plentiful.

Rise of Tyrannosaurus rex

This dynamic may explain the rise of the Tyrannosaurus rex in the Cretaceous period. As sauropod populations declined, predators like T. rex had to adapt to more challenging prey, leading to the development of traits such as immense size, binocular vision, and a jaw capable of crushing bones.