Paleontology in California
During the early Paleozoic, California was covered by a warm shallow sea inhabited by marine invertebrates such as ammonites, brachiopods, corals, and trilobites.
The state would come to be home to creatures such as camels, three-toed horses, mastodonts, oreodonts, saber-toothed cats, ground sloths, and dire wolves.
Major finds include the Pleistocene mammal fossils of the La Brea tar pits.
[2] During the early Paleozoic, California was covered by a warm shallow sea inhabited by marine invertebrates such as ammonites, brachiopods, and corals.
Deep and shallow marine deposits as well as estuaries and swamps could be found in Butte and Shasta Counties during this interval.
[5] During the Late Campanian and Maastrichtian California was home to evolutionarily advanced mosasaurs including Plesiotylosaurus and Plotosaurus.
[6][7] Abundant elasmosaur fossils belonging to a few genera including Hydrotherosaurus, Aphrosaurus, Fresnosaurus, and Morenosaurus have been unearthed here too.
The Coast and Transverse Mountains were created by the same geologic forces responsible for raising the Sierra Nevada during the Mesozoic.
[19] During the Middle Miocene, Los Angeles County was home to a diverse fauna of marine invertebrates including many kinds of gastropods and pelecypods.
[20] At the boundary between the Miocene and the Pliocene alder, cherry, Christmas berry, chumico, coffee berry, dogwood, elm, flannel bush, Catalina ironwood, California lilac, magnolia, mountain mahogany, manzanita, live oak, poplar, bush poppy, swamp cypress, sumac, desert sweet, sycamore, tupelo, and willow all grew around the San Francisco Bay Area.
[19] During the early Pliocene, the Berkeley Hills area was home to creatures such as camels, horses, mastodonts, and oreodonts.
[21] Middle Pliocene was home to creatures such as bear dogs, camels of various sizes, flamingos, ground sloths, mastodons, pronghorns, two different kinds of rhinoceros, and small rodents.
[22] This collection of fossils is known as the Black Hawk Ranch assemblages and is widely regarded as the best early Pleistocene fauna west of the Rocky Mountains.
[23] Since its discovery the Black Hawk Ranch assemblage has produced camels, primitive coyotes, deer, elk, horses, relatives of modern musk oxen, an unusual kind of pronghorn antelope, rodents, saber-teeth, and dire wolves.
[19] Other Pleistocene plants include the southernmost examples known of coast redwoods and a spectacular Douglas fir specimens from a tree with a trunk six feet in diameter and complete with its seeds and needles.
Scientific concepts such as deep time and faunal succession have precursors in the creation mythology of California's Achomawi or Pit River people.
The Pit River peoples thought local Cenozoic fossil acorns were left by oak trees from before the Great Change.
[27] In 1856 a new upper Miocene deposit preserving the remains of 18-inch oysters was discovered in the Kirker Pass of Contra Costa County.
[citation needed] On October 2, 1964, excavations on the site of Stanford University's campus uncovered the remains of an aquatic desmostyle mammal called Neoparadoxia.
