Brachiosaurus was a large dinosaur that lived during the late Jurassic period, around 154 to 150 million years ago. It was known for its long neck, which allowed it to reach high vegetation in trees. Unlike many other dinosaurs, Brachiosaurus had longer front legs than hind legs, giving it a unique, upright posture. This herbivorous dinosaur could grow up to 85 feet long and weigh as much as 56 tons. Fossils of Brachiosaurus have been found primarily in North America and Africa, providing valuable insights into the diversity of dinosaur life during its time.