About Apatosaurus
| Scientific Name (Genus) | Apatosaurus |
| Meaning of Name | Deceptive lizard apatē (deceptive) [Greek] - sauros (lizard) [Greek] |
| Classification | Saurischia, Sauropodomorpha, Diplodocidae |
| Total Length | Approx. 21-23m |
| Diet | Herbivorous |
| Period | Late Jurassic (approx. 152-151 million years ago) |
| Species Name | Apatosaurus ajax Apatosaurus louisae |
| Year of Paper Publication | 1877 |
| Genus Name Publication | Marsh, Othniel Charles (1877). Notice of new dinosaurian reptiles from the Jurassic formation. American Journal of Science and Arts. |
A Giant Sauropod of the Jurassic
Apatosaurus was a giant sauropod of the Diplodocidae family that lived in North America during the Late Jurassic. It was characterized by a thick, sturdy neck and a robust body, with an estimated weight of over 20 tons. Its scientific name means "deceptive lizard," a name given because the discovered bones were initially difficult to distinguish from those of the marine reptile Mosasaurus.
Skeletal studies have shown that it did not hold its neck high like a swan, as once thought, but rather held it straight out, nearly parallel to the ground. This suggests that it fed on low-lying plants like ferns, rather than the leaves of tall trees.
Furthermore, since Apatosaurus did not have complex teeth, it is believed to have used "gastroliths" (stomach stones) to aid digestion. These stones would grind up plant matter in its stomach.
A Supersonic Tail and Incredible Growth
Similar to the skull of Diplodocus, but more robust.
The tail of Apatosaurus was extremely long and tapered to a whip-like end. It is thought to have been a powerful weapon for self-defense against predators like Allosaurus, but that's not all. Recent simulation studies have shown that by whipping the tip of its tail at supersonic speeds, it could have generated a cannon-like sonic boom. This sound may have been used for communication with other Apatosaurus or for intimidating enemies.
Studies of bone growth rings have revealed that Apatosaurus grew at an astonishing rate. Hatchlings were only about 30 cm long, but they experienced a rapid growth spurt between the ages of 8 and 12, gaining up to 5 tons in weight per year during this period. They reached a colossal size of over 20 meters in just about 15 years, after which their growth slowed. This rapid growth is thought to have been a survival strategy to quickly outgrow predators.
The Brontosaurus Naming Issue
Labeled as Brontosaurus
Apatosaurus has long been confused with the famous "Brontosaurus" (Thunder Lizard). Apatosaurus was named in 1877, and Brontosaurus two years later in 1879, both by paleontologist Othniel Charles Marsh. However, in 1903, it was concluded that Brontosaurus was merely a juvenile Apatosaurus, and the name was synonymized with the earlier-named Apatosaurus, causing the name "Brontosaurus" to be officially abandoned.
However, in 2015, a study that re-examined a vast number of specimens was published, proposing that "Brontosaurus is a distinct genus from Apatosaurus, with different skeletal features," and the genus name "Brontosaurus" was revived after 112 years. This theory has been met with some opposition, and the debate continues among experts today.