Dinosaur bonesFossil dinosaur skeleton near Tuba City, Arizona. Photograph
Uintathere, an extinct rhinocerus of North AmericaExtinct species of rhinocerus, Uintathere, ancient Wyoming and Utah. Hand-colored halftone reproduction of an 1890s Charles Knight illustration
Allosaurus modelModel of Allosaurus dinosaur at the National Zoo, Washington DC. Photograph
Human evolution as described in the 1870sTheory of the " descent of man" as illustrated in the 1870s. Hand-colored woodcut of a 19th-century illustration
Wooly mammoth fossil, South DakotaFossil skull and tusks of a wooly mammoth in an excavation at Mammoth Site, Hot Springs, South Dakota. Digital photograph
Iguanodon, a large herbivorous dinosaur of the early Cretaceous period, a restoration by Woodward, 1890s. Hand-colored engraving of a 19th-century illustration
Wooly mammoth. Hand-colored woodcut of a 19th-century illustration
Elothere, an extinct hog of North AmericaExtinct species of giant pig, Elothere, of ancient South Dakota. Hand-colored halftone reproduction of an 1890s Charles Knight illustration
Titanothere, an extinct rhinocerus of North AmericaExtinct species of rhinocerus, Titanothere, ancient South Dakota. Hand-colored halftone reproduction of an 1890s Charles Knight illustration
Dinosaur footprintFossil dinosaur footprint near Tuba City, Arizona. Photograph
Dinosaur footprintsFossil dinosaur footprints near Tuba City, Arizona. Photograph
Protoceras, an extinct mammal of North AmericaExtinct species of pronghorn, Protoceras, ancient South Dakota Black Hills. Hand-colored halftone reproduction of an 1890s Charles Knight illustration