Sauroposieden was a sauropod of immense proportions. It was 100 feet long and was 50 feet tall. To had a neck 40 feet long, making it one of the longest necks of any dinosaur. It was a Brachiosaur to be exact, and it was the biggest. Sauroposieden has only been found by a neck vertebra 10 feet long and other small bits of bone. I lived in early Cretaceous North America and had almost no predators. Almost. A large pack of Acrocanthosaurus could take down a Sauroposiden despite its enormous size. Nothing is safe in the dinosaur period, nothing.