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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...

seal, in zoology

(Encyclopedia)seal, carnivorous aquatic mammal with front and hind feet modified as flippers, or fin-feet. The name seal is sometimes applied broadly to any of the fin-footed mammals, or pinnipeds, including the wa...

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...

Lamarck, Jean Baptiste Pierre Antoine de Monet, chevalier de

(Encyclopedia)Lamarck, Jean Baptiste Pierre Antoine de Monet, chevalier de zhäN bätēstˈ pyĕr äNtwänˈdə mônāˈ, shəvälyāˈ də lämärkˈ [key], 1744–1829, French naturalist. He is noted for his stud...

Pauling, Linus Carl

(Encyclopedia)Pauling, Linus Carl pôˈlĭng [key], 1901–94, American chemist, b. Portland, Oreg. He was one of the few recipients of two Nobel Prizes, winning the chemistry award in 1954 and the peace prize in 1...

ground squirrel

(Encyclopedia)ground squirrel, name applied to certain terrestrial rodents of the squirrel family. In North America the name refers to members of the genus Citellus and sometimes to the closely related genera Tamia...

symmetry

(Encyclopedia)symmetry, generally speaking, a balance or correspondence between various parts of an object; the term symmetry is used both in the arts and in the sciences. In art and design, it is often used in a s...

aging

(Encyclopedia)aging, in biology, cumulative changes in an organism, organ, tissue, or cell leading to a decrease in functional capacity. In humans, aging is associated with degenerative changes in the skin, bones, ...

Newcastle upon Tyne

(Encyclopedia)Newcastle upon Tyne, city and metropolitan borough (1991 pop. 199,064), NE England, on the Tyne River. The city is an important shipping and trade center. The famous coal-shipping industry began in th...

Le Pen, Jean-Marie

(Encyclopedia)Le Pen, Jean-Marie zhŏnˌ-märēˈ lə pĕn, pŏN [key], 1928–, French politician. He graduated from law school, was elected (1956) a parliamentary deputy, and criticized President de Gaulle's Alge...