Original: Apatosaurus (), also known by the popular but obsolete synonym Brontosaurus, is a genus of sauropod dinosaur that lived about, during the Jurassic Period (Kimmeridgian and Tithonian ages).
Simplified: Another dinosaur species discovered in 1994 was at first named A. yahnahpin, but in 1998, it was renamed Eobrontosaurus yahnahpin.