article: Charles R. Knight
links: Yale University La Brea Tar Pits Apatosaurus Ray Harryhausen National Geographic Deinonychus Triceratops Field Museum of Natural History Steven Spielberg Washington D.C. Brookfield Zoo Willis O'Brien Agathaumas Allosaurus Tyrannosaurus Bronx Zoo United States American Museum of Natural History Smilodon Lincoln Park Chicago, Illinois Los Angeles County Americans Manhattan, New York Smithsonian Institution Mammoth Metropolitan Museum of Art Painting Brooklyn, New York Cainozoic Pittsburgh, Pennsylvania Indiana University Robert Bakker Dryptosaurus