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San Timoteo Formation
The San Timoteo Formation, also called the San Timoteo Beds, is a geologic formation in California. History Part of the wider San Timoteo Badlands, San Timoteo Formation was initially excavated in San Timoteo Canyon under by a team sponsored by Childs Frick from 1916 to 1921. Geology The San Timoteo Formation represents Pliocene and Early Pleistocene sediments, mostly sandstone. The Formation overlies the late Miocene and early Pliocene Mt. Eden Formation (Jack Rabbit Trail & Eden Hot Springs localities, corresponding to the Hemphillian and Blancan faunal stages). Fossils Fossils of Irvingtonian prehistoric mammals were found in the San Timoteo Formation (El Casco, Mammoth and Shutt Ranch localities). These include: * ''Canis edwardii'' (Edward's wolf) * ''Microtus sp.'' (vole) * '' Ondatra idahoensis'' (muskrat) * ''Mictomys kansasensis'' (bog lemming) * '' Erethizon cascoensis'' (porcupine) * “Plesippus” fracescana (three-toed horse) * '' Equus bautistensis'' (ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formation (stratigraphy)
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness (geology), thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microtus
''Microtus'' is a genus of voles found in North America, Europe and northern Asia. The genus name refers to the small ears of these animals. They are stout rodents with short ears, legs and tails. They eat green vegetation such as grasses and sedges in summer, and grains, seeds, root and bark at other times. The genus is also called "meadow voles". There is some disagreement on the definitive list of species in this genus, and which subgenera are recognized. The American Society of Mammalogists recognizes the following 60 species, with discrepancies as noted: Subgenus ''Blanfordimys'' * Afghan vole (''Microtus afghanus'') * Bucharian vole (''Microtus bucharensis'') * Juniper vole (''Microtus yuldaschi'') Subgenus ''Euarvicola'' * Short-tailed field vole (''Microtus agrestis'') * Mediterranean field vole (''Microtus lavernedii'') * Portuguese field vole (''Microtus rozianus'') Subgenus ''Hyrcanicola'' (not recognized by the ASM, listed in subgenus ''Microtus'') * Schelkovni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Fossiliferous Stratigraphic Units In California
This article contains a list of fossil-bearing stratigraphic units in the state of California, U.S. Sites See also * Paleontology in California References * {{DEFAULTSORT:Fossiliferous stratigraphic units in California California Stratigraphic units A stratigraphic unit is a volume of Rock (geology), rock of identifiable origin and relative age range that is defined by the distinctive and dominant, easily mapped and recognizable petrography, petrographic, lithology, lithologic or paleontology, ... Fossiliferous stratigraphic units California geography-related lists United States geology-related lists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homotherium
''Homotherium'' is an extinct genus of Homotherini, scimitar-toothed cat belonging to the extinct subfamily Machairodontinae that inhabited North America, Eurasia, and Africa, as well as possibly South America during the Pliocene and Pleistocene epochs from around 4 million to 12,000 years ago. It was one of the last surviving members of the subfamily alongside the more famous sabertooth ''Smilodon'', to which it was not particularly closely related. It was a large cat, comparable in size to a lion, functioning as an apex predator in the ecosystems it inhabited. It had an elongate neck and relatively elongate legs, a relatively short back and a very short tail, with the mummy of a ''H. latidens'' cub of Late Pleistocene age found in Siberia having a plain dark brown coat colour. In comparison to ''Smilodon'', the canines of ''Homotherium'' were shorter, though still longer than those of living cats, and it is suggested to have had a different ecology from ''Smilodon'' as a pursuit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smilodon Gracilis
''Smilodon'' is an extinct genus of felids. It is one of the best known saber-toothed predators and prehistoric mammals. Although commonly known as the saber-toothed tiger, it was not closely related to the tiger or other modern cats, belonging to the extinct subfamily Machairodontinae, with an estimated date of divergence from the ancestor of living cats around 20 million years ago. ''Smilodon'' was one of the last surviving machairodonts alongside ''Homotherium''. ''Smilodon'' lived in the Americas during the Pleistocene to early Holocene epoch (2.5 mya – at latest 8,200 years ago). The genus was named in 1842 based on fossils from Brazil; the generic name means or combined with . Three species are recognized today: ''S. gracilis'', ''S. fatalis'', and ''S. populator''. The two latter species were probably descended from ''S. gracilis'', which itself probably evolved from ''Megantereon''. The hundreds of specimens obtained from the La Brea Tar Pits in Los Angeles constit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammoth
A mammoth is any species of the extinct elephantid genus ''Mammuthus.'' They lived from the late Miocene epoch (from around 6.2 million years ago) into the Holocene until about 4,000 years ago, with mammoth species at various times inhabiting Africa, Asia, Europe, and North America. Mammoths are distinguished from living elephants by their (typically large) spirally twisted tusks and in some later species, the development of numerous adaptions to living in cold environments, including a thick layer of fur. Mammoths and Asian elephants are more closely related to each other than they are to African elephants. The oldest mammoth representative, '' Mammuthus subplanifrons'', appeared around 6 million years ago during the late Miocene in what is now southern and Eastern Africa.'''' Later in the Pliocene, by about three million years ago, mammoths dispersed into Eurasia, eventually covering most of Eurasia before migrating into North America around 1.5–1.3 million year ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megalonyx
''Megalonyx'' (Greek, "great-claw") is an extinct genus of ground sloths of the family Megalonychidae, native to North America. It evolved during the Pliocene Epoch and became extinct at the end of the Late Pleistocene, living from ~5 million to ~13,000 years ago. The type species, ''M. jeffersonii'' (also called Jefferson's ground sloth), the youngest and largest known species, measured about in length and weighed up to . ''Megalonyx'' is suggested to have descended from '' Pliometanastes,'' a genus of ground sloth that had arrived in North America during the Late Miocene around 9 million years ago, prior to the main phase of the Great American Interchange. ''Megalonyx'' had the widest distribution of any North American ground sloth, having a range encompassing most of the contiguous United States, extending as far north as Alaska during warm interglacial periods. ''Megalonyx'' is notable for having been originally described by future U.S. President Thomas Jefferson in 1799 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Odocoileus
''Odocoileus'' is a genus of medium-sized deer (family Cervidae) containing three species native to the Americas The Americas, sometimes collectively called America, are a landmass comprising the totality of North America and South America.''Webster's New World College Dictionary'', 2010 by Wiley Publishing, Inc., Cleveland, Ohio. When viewed as a sing ....''Odocoileus'' Mammal Species of the World, 3rd Edition [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tapirus Merriami
''Tapirus merriami'', commonly called Merriam's tapir, is an extinct species of tapir which inhabited North America during the Pleistocene. Early history Tapirs have a long history on the North American continent. Fossils of ancient tapirs in North America can be dated back to 50 million-year-old Eocene rocks on Ellesmere Island, Canada, which was then a temperate climate. By 13 million years before present, tapirs very much like extant tapirs existed in Southern California.M. Colbert and R. Schoch 1998. Tapiroidea and other moropomorphs. In: C. Janis, K. Scott, L. Jacobs, (eds) Evolution of Tertiary Mammals of North America. Volume I: Terrestrial carnivores, ungulates, and ungulate like mammals. Cambridge University Press. During the Pleistocene epoch, four species of tapir are known to have inhabited North America. Along with ''T. merriami'', '' Tapirus californicus'' also lived in California, ''Tapirus veroensis'' was found in Florida, Georgia, Kansas, Missouri and Tennessee, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equus Scotti
''Equus scotti'' (translated from Latin as Scott's horse, (2003) ''Annotated Bibliography of Quaternary Vertebrates of Northern North America: With Radiocarbon Dates'', University of Toronto Press, 539 pages named after vertebrate paleontologist William Berryman Scott) is an extinct species of horse native to Pleistocene North America. Evolution ''Equus scotti'' is a true caballine horse that is more closely related to modern horses than to zebras and asses. ''Equus scotti'' may be synonymous with '' Equus lambei,'' another generally smaller horse known from the Pleistocene of North America, but this is uncertain. Although it has been suggested that ''Equus scotti'' may be synonymous with living ''Equus ferus'', North American horses diverged from their Eurasian counterparts around 800,000 years ago, following the first dispersal of horses out of North America, with some interbreeding after the initial split. The earliest remains of the species are known from the late Blancan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erethizon
''Erethizon'' is a genus of New World porcupine and the only one of its family to be found north of southern Mexico. The North American porcupine ''(Erethizon dorsatum)'' is the only extant species, but at least 4 extinct relatives are known, the oldest dating to the Late Pliocene. Porcupines entered North America during the Great American Interchange after the Isthmus of Panama The Isthmus of Panama, historically known as the Isthmus of Darien, is the narrow strip of land that lies between the Caribbean Sea and the Pacific Ocean, linking North America, North and South America. The country of Panama is located on the i ... rose 3 million years ago. Early species of the genus retained an elongate tail, unlike ''E. dorsatum''. References {{Taxonbar, from=Q732499 Rodent genera Mammal genera with one living species Taxa named by Frédéric Cuvier Erethizontidae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muskrat
The muskrat or common muskrat (''Ondatra zibethicus'') is a medium-sized semiaquatic rodent native to North America and an introduced species in parts of Europe, Asia, and South America. The muskrat is found in wetlands over various climates and habitats. It has crucial effects on the ecology of wetlands, and is a resource of food and fur for humans. Adult muskrats weigh , with a body length (excluding the tail) of . They are covered with short, thick fur of medium to dark brown color. Their long tails, covered with scales rather than hair, are laterally compressed and generate a small amount of thrust, with their webbed hind feet being the main means of Aquatic locomotion, propulsion, and the unique tail mainly important in directional stability. Muskrats spend most of their time in the water and can swim underwater for 12 to 17 minutes. They live in families of a male and female pair and their young. They build nests to protect themselves from the cold and predators, often ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
