dinosaur

/ˌdaɪnəˈsɔər/

/ˈdaɪnəsɔ/

Other forms: dinosaurs

If you've ever seen Jurassic Park, you know that dinosaurs were large reptilian creatures that walked the earth during the Mesozoic era that ran from 245 million to 68 million years ago and included the Triassic, Jurassic, and Cretaceous periods.

The ancient Greeks had no knowledge of dinosaurs that we know of, but they unknowingly contributed to the word dinosaur. It was cobbled together in 1841 by British scientist Sir Richard Own, using the words deinos, meaning "terrible" and sauros meaning "lizard." All are gone—at least in their original form, although it is thought they simply evolved into other, present-day animals. The word dinosaur is often used for someone who is old-fashioned or unable to adapt to modern times.

Definitions of dinosaur

1. noun

   any of numerous extinct terrestrial reptiles of the Mesozoic era
   types:

   ornithischian, ornithischian dinosaur

   herbivorous dinosaur with a pelvis like that of a bird

   iguanodon

   massive herbivorous bipedal dinosaur with a long heavy tail; common in Europe and northern Africa; early Cretaceous period

   saurischian, saurischian dinosaur

   herbivorous or carnivorous dinosaur having a three-pronged pelvis like that of a crocodile

   diplodocus

   a huge quadrupedal herbivore with long neck and tail; of late Jurassic in western North America

   titanosaur, titanosaurian

   amphibious quadrupedal herbivorous dinosaur with a long thin neck and whiplike tail; of the Cretaceous mostly in the southern hemisphere

   argentinosaur

   huge herbivorous dinosaur of Cretaceous found in Argentina

   ground-shaker, seismosaur

   huge herbivorous dinosaur of the Cretaceous found in western North America

   pisanosaur, pisanosaurus

   primitive dinosaur found in Argentina

   staurikosaur, staurikosaurus

   primitive dinosaur found in Brazil

   armored dinosaur

   dinosaurs having bony armour

   bone-headed dinosaur

   bipedal herbivorous dinosaurs with bony crowns

   ceratopsian, horned dinosaur

   any of several four-footed herbivorous dinosaurs with enormous beaked skulls; of the late Cretaceous in North America and Mongolia

   ornithopod, ornithopod dinosaur

   bipedal herbivorous dinosaur

   duck-billed dinosaur, hadrosaur, hadrosaurus

   any of numerous large bipedal ornithischian dinosaurs having a horny duck-like bill and webbed feet; may have been partly aquatic

   sauropod, sauropod dinosaur

   very large herbivorous dinosaur of the Jurassic and Cretaceous having a small head a long neck and tail and five-toed limbs; largest known land animal

   genus Argentinosaurus

   enormous dinosaur of the middle Cretaceous found in Argentina

   bird-footed dinosaur, theropod, theropod dinosaur

   any of numerous carnivorous dinosaurs of the Triassic to Cretaceous with short forelimbs that walked or ran on strong hind legs

   type of:

   archosaur, archosaurian, archosaurian reptile

   extinct reptiles including: dinosaurs; plesiosaurs; pterosaurs; ichthyosaurs; thecodonts