The physical processes that control the composition and structure of the Earth’s crust. Tectonics include the movement of lithospheric plates, the faulting and folding resulting from it, and mountain building.

At roughly 2.2-1.5 million years old, this Late Pliocene to Pleistocene-aged formation is located in the Central Valley of California. This formation is characterized by sandstone, sand, and alluvium and is largely non-marine in origin and contains a variety of freshwater invertebrate fossils and vertebrate fossils.

A map showing the landscape of an area, including the presence or absence of hills and the slopes between high and low areas. You can find many digital topographic maps on the USGS’ topoView. 

An extinct marine invertebrate belonging to the Class Trilobita of the Phylum Arthropoda, and characterized by a three-part body and an exoskeleton divided longitudinally into three lobes. Trilobites were one of the most successful early animals, crawling over the ocean floor for over 270 million years until they went extinct at the end of the Paleozoic Era, 252 million years ago. 

Trilobites were primitive arthropods distantly related to horseshoe crabs. As bottom dwellers, they were present in a variety of environments. Like crabs and lobsters, trilobites molted their exoskeletons when they grew. Most fossils of trilobites are actually molts, broken as they were shed off the trilobite. Thus, it is common to find only parts of trilobites, such as the head, mid-section, or tail.

Fossil that records the actions of organisms, such as footprints, trails, trackways, and burrows.