Brachiosaurus lived during the Late Jurassic Period, around 154-150 million years ago. This dinosaur roamed the floodplains and forests of what is now North America, particularly in regions that are now part of Colorado, Utah, and Wyoming.

Brachiosaurus was a gigantic dinosaur, with some estimates suggesting it could reach lengths of up to 85 feet and weigh as much as 62 tons. It had a distinctive body structure, characterized by long front legs and a shorter tail, giving it a more upright posture compared to other sauropods. Its neck was extremely long, allowing it to reach high into the trees to feed on vegetation.

Brachiosaurus was herbivorous, feeding primarily on leaves, needles, and other plant materials from tall coniferous trees, cycads, and ginkgoes. Its peg-like teeth were adapted for stripping vegetation rather than chewing, and it likely swallowed stones (gastroliths) to help grind up plant material in its stomach.

Fun Fact:
Brachiosaurus is one of the few dinosaurs known to have had front legs longer than its hind legs. This unique adaptation allowed it to browse foliage at heights that other herbivores couldn't reach, reducing competition for food.

The first Brachiosaurus fossils were discovered in 1900 by paleontologist Elmer S. Riggs in the Grand River Canyon of western Colorado. The genus name Brachiosaurus means "arm lizard," referring to its unusually long front limbs.

What Happened to Them:
Brachiosaurus, like many other dinosaurs, went extinct at the end of the Cretaceous Period around 65 million years ago. The cause of their extinction is widely believed to be a combination of catastrophic events, including a massive asteroid impact and volcanic activity, which led to dramatic climate changes and the collapse of ecosystems.