Giraffatitan, meaning "giant giraffe", is a genus of sauropod dinosaur that lived during the late Jurassic Period (Kimmeridgian–Tithonian stages). It was originally named as an African species of Brachiosaurus (B. brancai) but this has since been changed. Giraffatitan was for many decades known as the largest dinosaur but recent discoveries of several larger dinosaurs prove otherwise: giant titanosaurians (Argentinosaurus, Puertasaurus and Futalognkosaurus) appear to have surpassed Giraffatitan in terms of sheer mass also the sauropod dinosaur Sauroposeidon is estimated to be taller and possibly heavier than Giraffatitan.