Giraffatitan (Greek for "giant giraffe"); pronounced jih-RAFF-ah-tie-tan
Woodlands of Africa
Late Jurassic (150 million years ago)
Size and Weight:
About 80 feet long and 30 tons
Large size; long, massive neck
Giraffatitan is one of those dinosaurs that dances around the fringes of respectability: its existence is attested to by numerous fossil specimens (found in the environs of the African nation of Tanzania), but the suspicion lingers that it may actually have been a species of an existing genus of sauropod, most likely Brachiosaurus. However Giraffatitan winds up being classified, there's no doubt that it was one of the tallest (if not one of the heaviest) sauropods ever to walk the earth, with a hugely elongated neck that would have allowed it to hold its head more than 40 feet above ground level (a pose that most paleontologists think is unrealistic, considering the metabolic demands this would have placed on Giraffatitan's heart).