Dinosaur Facts: Apatosaurus (the Brontosaurus)

Nicknamed the “Deceptive Lizard”, the Apatosaurus is better known as the Brontosaurus in mainstream circles , the harmless giant of a dinosaur. This plant-eating creature was one of the largest land animals at one time. In this article, you will learn more about this imposing member of the dinosaur world.

Body Details

The Brontosaurus was one of the biggest of land animals that ever dwelled on the earth. Standing 70 to 90 feet long and around 15 feet tall at the hips, the Brontosaurus reached weights of between 33 and 38 tons. The head of the dinosaur was pretty small , measuring less than 2 feet long with a long skull and extremely tiny brain.

With 15 vertebrae maintaining its length, the Brontosaurus had a long neck and lengthy whip-like tail around 50 feet long. A long neck helped the Brontosaurus against attacks from the scariest meat-eaters during their time (like the Allosaurus), which had a difficult time attacking the head or neck of the long-necked dinosaur. Like many dinosaur species similar to the Brontosaurus, they had four massive, column-like legs, where the hind legs were larger than the front legs. Fossilized Apatosaurus footprints (called trackways) discovered in Colorado measured about a yard wide , showing how great their physical characteristics were.

Additional physical characteristics include a hollow backbone, peg-like teeth situated in the front of the jaws, and had nostrils positioned on the top of the head.


The Apatosaurus lived during the late Jurassic Period (about 157 to 146 million years ago) and is believed to have traveled in herds. However, bonebeds consisting of Apatosaurus fossils have not been found yet. Some researchers believe that the creature was a solitary animal. The dinosaur (like other sauropods) hatched from huge eggs that measured up to 1 foot wide. The eggs were discovered in a linear pattern that did not gather in nests. It is thought that the dinosaur laid their eggs while still walking and did not stay behind to take care of their offspring.  


The Brontosaurus only ate plants with a main diet that consisted of conifers, tree leaves, club mosses, horsetails, and ferns. In order to sustain its body weight, the dinosaur had to eat a great deal of plant material. This meant that the majority of the day was spent grazing, using blunt-like teeth shaped like a pencil to strip and gather foliage. The process was comparable to the action of a garden rake.

Brontosaurus Fossils

The identification of the Apatosaurus came in 1877 when a paleontologist named Othniel C. Marsh described and named the dinosaur. The dinosaur’s name translated into “deceptive lizard” because their remains were easily mistaken for the bones of other sauropods. After a couple of years had passed, he gave details on and named another dinosaur fossil (the Brontosaurus), which translated into “thunder lizard.” In the end, it turned out that the two dinosaurs were actually belonging to the same genus. The earlier scientific name of Apatosaurus was kept and the name Brontosaurus was no longer used as a separate name.  

The first nearly complete Apatosaurus fossil was found by Earl Douglass in the Morrison Formation in Colorado, which was called the Carnegie quarry at the time of discovery. Apatosaurus fossils were located in Colorado, Oklahoma, Utah, and Wyoming. After the first discovery, more species of Apatosaurus were identified as Apatosaurus ajax , (found in Colorado), A. excelsus (located in Oklahoma, Utah, and Wyoming), A. louisae (found in Colorado), and A. yahnahpin  (situated in Wyoming).