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Paleontology in California refers to paleontological research occurring within or conducted by people from the U.S. state of California. California contains rocks of almost every age from the Precambrian to the Recent.〔 Precambrian fossils are present but rare 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. During the Carboniferous and Permian swamps covered areas of the state no longer submerged by the sea. During the Mesozoic, California continued to comprise both marine and terrestrial habitats. Local marine life included ammonites, marine reptiles, and oysters. On land, dinosaurs roamed among cycads and conifers. During the Cenozoic, sea levels rose and fell over time, so the state was home to a variety of ancient environments including shallow seas, estuaries and dry land. The state would come to be home to creatures such as camels, three-toed horses, mastodonts, oreodonts, saber-teeth, ground sloths, and dire wolves. Local Native Americans devised myths to explain local fossils, many containing themes paralleling modern scientific discoveries. Local fossils came to the attention of formally trained scientists by the mid-19th century. Major finds include the Pleistocene mammal fossils of the La Brea tar pits. The Pleistocene saber-toothed cat ''Smilodon fatalis'' is the California state fossil. ==Prehistory== Precambrian fossils are present but rare in California.〔 During the early Paleozoic, California was covered by a warm shallow sea inhabited a marine invertebrates such as ammonites, brachiopods, and corals.〔 At least two different genera of trilobites lived in San Bernardino County during the Early Cambrian.〔 By Mississippian times California was home to brachiopods and corals that would later silicify.〔 Later, during the Carboniferous and Permian periods northern California had a variety of environments. Deep and shallow marine deposits as well as estuaries and swamps could be found in Butte and Shasta Counties during this interval.〔 Later, during the Pennsylvanian, both the corals and brachiopods were still living in the state.〔 California was a region of geologic upheaval during the Mesozoic, including both Mountain formation and volcanism. The Sierra Nevada began forming at this time. Mesozoic California included areas of both marine and terrestrial environments. The local seas were home to a variety of marine invertebrates and marine reptiles. The terrestrial flora included plants such as conifers, cycads, and ginkgoes.〔 Radiolaria were widespread in California during the Jurassic. Some of the best fossilized specimens come from the Stow Lake area and Strawberry Hill in Golden Gate Park. During the Cretaceous invertebrates such as ammonites and pearl oysters and lived in California.〔 Both coiled and uncoiled ammonites were preserved in California's Late Cretaceous deposits.〔 During the Late Campanian California was home to evolutionarily advanced mosasaurs including ''Plesiotylosaurus'' and ''Plotosaurus''.〔 On land, a variety of dinosaurs inhabited the state.〔 Among them were the Ankylosaur ''Aletopelta'',〔 many duck-billed dinosaurs,〔 and probably the tyrannosaur ''Albertosaurus''.〔 Into the Cenozoic era, California was still very geologically active. The Coast and Transverse Mountains were created by the same geologic forces responsible for raising the Sierra Nevada during the Mesozoic. Sea levels rose and fell over time, so the state was home to a variety of ancient environments including shallow seas, estuaries and dry land.〔 More than 2,300 species of Tertiary insects have been documented in the ancient tar deposits of California.〔 Middle Eocene invertebrates of California included corals, gastropods, and pelecypods.〔 At least some of these corals were solitary.〔 Oligocene plant fossils include leaves, fruit and wood.〔 During the Middle Miocene, Los Angeles County was home to a diverse fauna of marine invertebrates including many kinds of gastropods and pelecypods. Many of these fossils are very well preserved.〔 Middle Miocene acorn barnacles were preserved in Santa Clara County. During the Late Miocene 18 inch long oysters lived in Contra Costa County.〔 In Sonoma County freshwater gastropods and pelecypods were preserved. Sand dollars also inhabited California during the Late Miocene.〔 California was home to aquatic mammals such as the dugongid ''Dusisiren'' and the desmostyle ''Paleoparadoxia'' during the Miocene.〔 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.〔 An abundance of Pliocene plants are known from San Francisco.〔 During the early Pliocene, the Berkeley Hills area was home to creatures such as camels, horses, mastodonts, and oreodonts. Near Mount Diablo deposits of similar age provide evidence for at least three different kinds of camel, cranes, a fox, a primitive ground squirrel, a small beaver, horses (with the three-toed horse ''Hipparion forcei'' being the most common), hyena-like animals, a lizard, abundant mastodonts, mountain lion-like cats, a mustelid, oreodonts, peccaries, rabbits, raccoon-like animals, a ring-tailed cat, and possible saber-toothed cats.〔 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.〔 The late Pliocene saw the appearance of many of California's modern animals, however there were also giant tortoises among the contemporary fauna.〔 During the Pliocene, the Scotia–Eureka area was home to marine invertebrates.〔 During the Late Pliocene pelecypods and gastropods are known.〔 At the same time, ark shells were preserved in a wide variety of places in California.〔 By the Quaternary, California's wildlife had taken on a relatively modern aspect. The landscape included lakes and rivers, as well as glaciers. Local wildlife included camels, saber-teeth, and mammoths.〔 Pleistocene]invertebrates have been found in great abundance near Ventura.〔 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.〔 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.〔 Pleistocene plant fossils are widespread in the Bay area. Twelve species of modern tree are known from near Tomales.〔 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.〔 Other Pleistocene invertebrates of California included hardshell cockles, spiny cockles, and oysters.〔 Late Pleistocene fossils are widespread in California.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Paleontology in California」の詳細全文を読む スポンサード リンク
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