Rahonavis it means "Cloud-menace bird" was a ancient bird/dinosaur with sickle-like claws on its feet. It was middle between a dromaeosaurid dinosaur and a bird

Rajasaurus narmadensis was a heavy-boned meat-eating dinosaur that lived during the late Cretaceous era.

Ramapithecus was an arboreal (tree-living) primate that was perhaps an ancestor of modern-day orangutans

Rapetosaurus was a sauropod long-necked, plant-eating dinosaur that lived throughout the late Cretaceous period, about 70-65 million years back.

Raptor is an casual term that several people use to refer to the Dromaeosaurid dinosaurs, like Velociraptor, Utahraptor, Deinonychus, and others.

Raptorex kriegsteini was a minute, meat-eating dinosaur, a 3 m extended version of T. rex.

Rauisuchians were large-skulled archosaurs (not dinosaurs) from the mid to late Triassic period.

Rayososaurus was a large, diplodocid sauropod dinosaur from the early Cretaceous era, about 99 million years back.

Reptile it is cold-blooded animals with backbones

Revueltosaurus is a poorly-known ornithischian dinosaur that lived throughout the late Triassic period, about 220 million years back.

Rhabdodon was a small, iguanodontid ornithopod dinosaur from the untimely Cretaceous period, about 83 to 65 million years before.

Rhoetosaurus was a sauropod dinosaur from the middle Jurassic period, about 181 to 175 million years back.

Rileyasuchus was an early theropod dinosaur from the late Triassic era.

Rock Hammer about the size of a usual claw hammers, but heavier with a squared, dull end and a sharp pick on the opposite end.

Ruminant is an animal that digests its food numerous times. This food is typically tough plant material like grasses. It includes cows, sheep, antelopes, and camels.