Sauropods, those familiar plant-eating dinosaurs with long necks, long tails and four pillar-like legs, were the biggest land animals in Earth's history, reaching 100-120 feet (30-36 meters) long and weighing as much as a tractor-trailer.
A new study has calculated for the first time the number of different sauropod lineages that achieved whopping proportions - 36 of them in a span of about 100 million years bridging the Jurassic and Cretaceous periods. There was no one-size-fits-all evolutionary strategy to become immense, with these lineages distinct from one another despite sharing a general body plan.
"Sauropods aren't just the largest animals ever to walk the Earth. They earned that title independently more than 30 times throughout their evolutionary history," said palaeontologist Mike D'Emic of Adelphi University in New York, author of the study published in the journal Current Biology.
