There has been a ton of debate on whether or not the Brontosaurus truly existed. The confusion stemmed from 2 paleontologists: Othniel Marsh and 1883 and Elmer Riggs in 1903. Marsh is known for discovering the first Brontosaurus fossils back in 1879, thinking them to be that of a Brachiosaurus at the time.
Elmer Riggs originally thought that his finding was an Apatosaurus fossil. As it turned out, what he really found was a Brachiosaurus.
So why all of the confusion? As it turns out, paleontologists found that these sauropods were built similarly. In order to get our facts straight, let’s look at the characteristics of these sauropods (long-necked dinosaurs) and why it was really confusing to name them.
Let’s start with the Apatosaurus: When broken down, Apatosaurus translates to “deceptive lizard”. It was given this name by Marsh because some of the bones looked like those of mosasaurs, which were large aquatic reptiles. The Apatosaurus could be anywhere from about 67 to 75 feet in length. The main difference with Apatosaurus was its legs were sturdier and less lengthy than its counterpart Brachiosaurus. It also had a smaller head and had teeth that were more chiseled, making it a perfect candidate for an herbivore. Finally, according to research the Brachiosaurus probably did not hold its head high in the sky like the Brontosaurus due to blood pressure reasons.
Now the Brontosaurus and Apatosaurus have both had rough times staying separated; they are both Diplodocidae, which basically means they have long necks, short legs, and a whip for a tail. The difference: The Brontosaurus had a neck that was higher with less width. This was a good find because as it turns out, there are three different types of Brontosauri.
Finally, the Brachiosaurus literally breaks down to “arm lizard” because its forearms were longer than its hind legs, which made it rise a little taller and have a more angled body, including neck, toward the sky and different from the Brontosaurus whose legs were not as varied in length. It’s neck was like that of a giraffe so similar to the Brontosaurus which, again, spawned some earlier confusion. Thanks to studies done by paleontologists, we can all rest a little easier now.