Acrocanthosaurus

Part of speech: noun

Definitions

1. A large meat-eating dinosaur from the early Cretaceous period, known from fossils with tall spines along its back
2. An extinct theropod dinosaur of the early Cretaceous that walked on two powerful legs and hunted other reptiles
3. A giant predatory dinosaur of the early Cretaceous, named for the high neural spines on its vertebrae

Etymology: Acrocanthosaurus was named in 1950 by the American palaeontologist Samuel Paul Welles, though the name was not made official until 1989, when it was formally published. The name comes from ancient Greek roots: "akros" meaning "high" or "extreme," "akantha" meaning "thorn" or "spine," and "sauros" meaning "lizard." The "high spine" refers to the tall neural spines along the animal's back vertebrae, which were long enough to suggest a ridge or sail-like structure. Welles based the name on fossils found in Utah, where the first specimens had been unearthed. The creature itself lived roughly 113 to 110 million years ago, during the early Cretaceous, and was among the largest predators of its time in North America. Its name is a modern scientific coinage built from classical Greek elements, as is typical for dinosaur names, so the Greeks themselves knew nothing of it.