Definition

1. Noun:
   • An extinct marine reptile: A plesiosaurus is a type of prehistoric reptile that lived in the ocean. It is characterized by a very long neck, a small head, a short tail, and four large, paddle-shaped limbs used for swimming. It existed during the Jurassic and Cretaceous periods.

Examples of Usage

• Noun:
  • The museum's fossil exhibit features the skeleton of a plesiosaurus.
  • Scientists believe the plesiosaurus was a carnivore that hunted fish and other marine creatures.
  • The long neck of the plesiosaurus distinguishes it from other marine reptiles like the ichthyosaurus.

Advanced Usage

• In paleontological context: The term is used to describe a member of the broader order Plesiosauria.
  • The discovery of a new plesiosaurus species has provided insights into marine ecosystems of the Cretaceous period.

Variants and Related Words

• Plesiosaur (n): This is a more general term for any member of the order Plesiosauria, which includes both long-necked (plesiosauroids) and short-necked (pliosaurs) forms. "Plesiosaurus" is a specific genus within this order.
  • Plesiosaurs were among the top predators in Mesozoic seas.
• Plesiosaurian (adj): Relating to or characteristic of plesiosaurs.
  • The plesiosaurian fossils were remarkably well-preserved.

Synonyms

• Marine reptile: A general term for reptiles that lived in the ocean, such as ichthyosaurs, mosasaurs, and plesiosaurs.
• Sauropterygian: A member of the superorder Sauropterygia, which includes plesiosaurs and their relatives.

Related Phrases

• Plesiosaurus fossil: The preserved remains or impression of a plesiosaurus.
  • The plesiosaurus fossil was embedded in the cliff face.
• Plesiosaurus skeleton: The bony structure of a plesiosaurus.
  • The complete plesiosaurus skeleton is over five meters long.

Noun

1. extinct marine reptile with a small head on a long neck a short tail and four paddle-shaped limbs; of the Jurassic and Cretaceous