Mark Hallett

The most massive land animals ever to have lived, sauropods roamed widely across the continents through most of the "Age of Dinosaurs" from about 220 to 65 million years ago. They reached incredible sizes, giving rise to the question: Why were they so big? Early guesses suggested that they gained protection from predators by virtue of their size, which also allowed them to reach the tops of trees in order to eat leaves and conifer needles. More recent...