Jurassic Period

Dinosaurs of the Month

Apatosaurus

Time Period: Late Jurassic

Diet: Ate only plants, herbivore

Type: Sauropod

Name Meaning: Deceptive Lizard

Genus: Apatosaurus

Species: Apatosaurus ajax

Length: 75 feet

The Apatosaurus is one of the most famous dinosaurs. You may know this dinosaur by a different name, Brontosaurus, but these dinosaurs are the same. Paleontologist Othniel Marsh discovered two fossils of sauropods, but classified them as different dinosaurs, one was Apatosaurus, and the other was Brontosaurus. A later examination proved that these fossils were of the same species. Most scientists support this, however many people still use the name Brontosaurus because it is more familiar.

Allosaurus

Time Period: Late Jurassic

Diet: Ate only meat, carnivore

Type: Theropod

Name Meaning: Strange Lizard

Genus: Allosaurus

Species: Allosaurus fragilis

Length: 38 feet

The Allosaurus is one of the best known Carnosaurs. It was closely related to the Giganotosaurus. Allosaurus was the top predator in its environment, so it would mainly feed on herbivores like Stegosaurus. The Allosaurus was classified as Antrodemus for over half of the 20th century, but as more fossils were discovered, it was renamed Allosaurus. Allosaurus means “Strange Lizard,” and it was named when it was first discovered because it had a vertebrae that was different from any other dinosaur found at the time of its discovery.

Barosaurus

Time Period: Late Jurassic

Diet: Ate only plants, herbivore

Type: Sauropod

Name Meaning: Heavy Lizard

Genus: Barosaurus

Species: Barosaurus lentus

Length: 82-89 feet

The Barosaurus was a sauropod that lived in the late Jurassic period. It was an extremely large dinosaur, that was one of the biggest Jurassic dinosaurs. It’s name means “heavy lizard” because it was very heavy for its size.