Caves: Geological formations consisting of underground enclosures with access from the surface.Radiometric Dating: Techniques used to determine the age of materials, based on the content and half-lives of the RADIOACTIVE ISOTOPES they contain.Archaeology: The scientific study of past societies through artifacts, fossils, etc.Ursidae: The family of carnivorous or omnivorous bears, having massive bodies, coarse heavy fur, relatively short limbs, and almost rudimentary tails.History, Ancient: The period of history before 500 of the common era.Fossils: Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.PaintingsCypriniformes: An order of fish with 26 families and over 3,000 species. This order includes the families CYPRINIDAE (minnows and CARPS), Cobitidae (loaches), and Catostomidae (suckers).Neanderthals: Common name for an extinct species of the Homo genus. Fossils have been found in Europe and Asia. Genetic evidence suggests that limited interbreeding with modern HUMANS (Homo sapiens) took place.Characidae: A family of fresh water fish in the order CHARACIFORMES, which includes the Tetras.Amphipoda: An order of mostly marine CRUSTACEA containing more than 5500 species in over 100 families. Like ISOPODA, the other large order in the superorder Peracarida, members are shrimp-like in appearance, have sessile compound eyes, and no carapace. But unlike Isopoda, they possess thoracic gills and their bodies are laterally compressed.Geological Phenomena: The inanimate matter of Earth, the structures and properties of this matter, and the processes that affect it.Engraving and EngravingsPaleontology: The study of early forms of life through fossil remains.Geology: The science of the earth and other celestial bodies and their history as recorded in the rocks. It includes the study of geologic processes of an area such as rock formations, weathering and erosion, and sedimentation. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)