1. a large herbivorous sauropod dinosaur of the Jurassic period, characterized by a long neck and tail and columnar legs
Usage: also called brachiosaurus in older texts; paleontology term

Examples

• The apatosaur was one of the largest land animals ever to exist.
• Fossils of the apatosaur have been found in the Morrison Formation of North America.
• An apatosaur could weigh up to 30 tons and measure over 70 feet in length.
• The long neck of the apatosaur allowed it to reach vegetation high in trees.
• Museum displays often feature a skeletal reconstruction of an apatosaur.