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Plesiosaurus

(Encyclopedia)Plesiosaurus plēˌsēəsôrˈəs [key], genus of extinct predatory marine reptiles that arose in the Triassic period of geologic time and continued into the Jurassic and Cretaceous periods. Plesiosau...

continental drift

(Encyclopedia)CE5 Continental drift (arrows indicate the directions of motion of the landmasses) A. Proposed reconstruction of the supercontinent Pangaea indicating the major present landmasses B. Proposed recon...

Cretaceous period

(Encyclopedia)Cretaceous period krĭtāˈshəs [key], third and last period of the Mesozoic era of geologic time (see Geologic Timescale, tablegeologic timescale, table), lasting from approximately 144 to 65 millio...

Triassic period

(Encyclopedia)Triassic period trīăsˈĭk [key], first period of the Mesozoic era of geologic time (see Geologic Timescale, tablegeologic timescale, table) from 205 to 250 million years ago. Throughout the Triassi...

tuatara

(Encyclopedia)tuatara –tāˈrə [key], lizardlike reptile, Sphenodon punctatus, last survivor of the reptilian order Rhynchocephalia, which flourished in the early Mesozoic era before the rise of the dinosaurs. A...

cephalopod

(Encyclopedia)CE5 Internal anatomy of a squid, Loligo, representative mollusk of the class Cephalopoda cephalopod sĕfˈələpŏdˌ [key], member of the class Cephalopoda, the most highly organized group of mol...

Day, Clarence Shepard

(Encyclopedia)Day, Clarence Shepard, 1874–1935, American essayist, b. New York City, grad. Yale, 1896. His biographical sketches of his parents, God and My Father (1932), Life with Father (1935), and Life with Mo...

Jurassic period

(Encyclopedia)Jurassic period jərăsˈĭk [key] [from the Jura Mts.], second period of the Mesozoic era of geologic time, lasting from 213 to 144 million years ago. At the start of the Jurassic most of the contine...

reptile

(Encyclopedia)reptile, name for the dry-skinned, usually scaly, cold-blooded vertebrates (see Chordata) of the order Reptilia. Reptiles are found in a variety of habitats throughout the warm and temperate regions (...

dinosaur

(Encyclopedia)dinosaur dīˈnəsôr [key] [Gr., = terrible lizard], extinct land reptile of the Mesozoic era. The dinosaurs, which were egg-laying animals, ranged in length from 21⁄2 ft (91 cm) to about 127 f...