English: For over a hundred years, Brontosaurus excelsus was considered to be a species of the closely related genus Apatosaurus, and the name was therefore invalid. However, a 2015 analysis concluded that the two were separate genera, based on a variety of criteria, mainly in the shoulders and neck. Brontosaurus was a massive sauropod, reaching up to 22 m in length, and weighing around 17 t. Its head was small relative to its body, with a squared off snout lined with chisel-like teeth, well adapted for its herbivorous diet.