Dubbed Aardonyx celestae, the 195-million-year-old dinosaur had a lot of sauropod-like features, such as a robust skeleton for holding up its heft. (See extreme dinosaur pictures.)
Unlike sauropods, though, the newfound species walked on two legs and only dropped down on all fours, the new research shows. This means that walking on all fours started earlier in sauropod ancestors than previously thought, researchers say.
“What’s exciting about Aardonyx is it’s showing us that transition period … it’s the closest thing just before becoming the classic sauropod,” said study co-author Matthew Bonnan, a vertebrate paleobiologist at Western Illinois University.