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Santiago Formation, California
The Santiago Formation is a geologic formation in Orange and northwestern San Diego County, California. The siltstones, mudstones and sandstones of the formation preserve fossils of '' Walshina esmaraldensis'' and '' Diegoaelurus vanvalkenburghae'', dating back to the Late Eocene to Late Oligocene periods (Uintan to Duchesnean in the NALMA classification). at .org Depositional environment The only paleoenvironmental interpretation based exclusively on specimens from the Santiago Formation is a study of land snails from SDSNH locality 3276 (Member C,[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Formation
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 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 Abraham Gottlob Wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Period (geology)
The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronology (scientific branch of geology that aims to determine the age of rocks). It is used primarily by Earth scientists (including geologists, paleontologists, geophysicists, geochemists, and paleoclimatologists) to describe the timing and relationships of events in geologic history. The time scale has been developed through the study of rock layers and the observation of their relationships and identifying features such as lithologies, paleomagnetic properties, and fossils. The definition of standardized international units of geologic time is the responsibility of the International Commission on Stratigraphy (ICS), a constituent body of the International Union of Geological Sciences (IUGS), whose primary objective is to precisely define ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lycophocyon Skull Lateral
''Lycophocyon'' is an extinct genus of caniformian carnivoran from Middle Eocene (early Duchesnean and possibly late Uintan NALMA) deposits of San Diego County, California. ''Lycophocyon'' is known from the holotype UCMP 85202, a partial left and right dentary. Paratypes include UCMP 170713, SDSNH 107658, SDSNH 107659, SDSNH 107442, SDSNH 107443 and SDSNH 107444, partial dentaries, mandibles and other cranial remains, and SDSNH 107446 and SDSNH 107447, cranial and postcranial fragments. Many additional specimens are also known. All specimens were collected from numerous localities, all of them from the upper portions of "member C" of the Santiago Formation. It was first named by Susumu Tomiya in 2011 and the type species is ''Lycophocyon hutchisoni''. The generic name means "twilight dog" in Greek, in references to its occurrence on the west coast of North America, and its affinity to the Caniformia. The specific name honours the paleontologist J. Howard Hutchison. Phylog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caniformia
Caniformia is a suborder within the order Carnivora consisting of "dog-like" carnivorans. They include dogs (wolves, foxes, etc.), bears, raccoons, and mustelids. The Pinnipedia (seals, walruses and sea lions) are also assigned to this group. The center of diversification for the Caniformia is North America and northern Eurasia. Caniformia stands in contrast to the other suborder of Carnivora, the Feliformia ("cat-like" carnivorans), the center of diversification of which was in Africa and southern Asia. Description Most members of this group have nonretractile claws (the fisher, marten, sea otter ( forepaws only), red panda, and ringtail, and some foxes have retractile or semi-retractile claws) and tend to be plantigrade (with the exception of the Canidae). Other traits that separate the Caniformia from the Feliformia is that caniforms have longer jaws and more teeth, with less specialized carnassial teeth. They also tend more towards omnivory and opportunistic feeding, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lycophocyon
''Lycophocyon'' is an extinct genus of caniformian carnivoran from Middle Eocene (early Duchesnean and possibly late Uintan NALMA) deposits of San Diego County, California. ''Lycophocyon'' is known from the holotype UCMP 85202, a partial left and right dentary. Paratypes include UCMP 170713, SDSNH 107658, SDSNH 107659, SDSNH 107442, SDSNH 107443 and SDSNH 107444, partial dentaries, mandibles and other cranial remains, and SDSNH 107446 and SDSNH 107447, cranial and postcranial fragments. Many additional specimens are also known. All specimens were collected from numerous localities, all of them from the upper portions of "member C" of the Santiago Formation. It was first named by Susumu Tomiya in 2011 and the type species is ''Lycophocyon hutchisoni''. The generic name means "twilight dog" in Greek, in references to its occurrence on the west coast of North America, and its affinity to the Caniformia. The specific name honours the paleontologist J. Howard Hutchison. Phylo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holotype Of Diegoaelurus Vanvalkenburghae
A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several examples, but explicitly designated as the holotype. Under the International Code of Zoological Nomenclature (ICZN), a holotype is one of several kinds of name-bearing types. In the International Code of Nomenclature for algae, fungi, and plants (ICN) and ICZN, the definitions of types are similar in intent but not identical in terminology or underlying concept. For example, the holotype for the butterfly '' Plebejus idas longinus'' is a preserved specimen of that subspecies, held by the Museum of Comparative Zoology at Harvard University. In botany, an isotype is a duplicate of the holotype, where holotype and isotypes are often pieces from the same individual plant or samples from the same gathering. A holotype is not necessarily "typi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxyaenidae
Oxyaenidae ("sharp hyenas") is a family of extinct carnivorous placental mammals. Traditionally classified in order Creodonta, this group is now classified in its own order Oxyaenodonta ("sharp tooth hyenas") within clade Pan-Carnivora in mirorder Ferae. The group contains four subfamilies comprising fourteen genera. Oxyaenids were the first to appear during the late Paleocene in North America, while smaller radiations of oxyaenids in Europe and Asia occurred during the Eocene. Etymology The name of order Oxyaenodonta comes , name of hyena genus ''Hyaena'' and . The name of family Oxyaenidae comes , name of hyena genus ''Hyaena'' and taxonomic suffix ":wikt:-idae#Suffix, -idae". Description They were superficially cat-like mammals that plantigrade, walked on flat feet, in contrast to modern cats, which digitigrade, walk and run on their toes. Anatomically, characteristic features include a short, broad skull, deep jaws, and teeth designed for crushing rather than shearing, as in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dentary
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movable bone of the skull (discounting the ossicles of the middle ear). It is connected to the temporal bones by the temporomandibular joints. The bone is formed prenatal development, in the fetus from a fusion of the left and right mandibular prominences, and the point where these sides join, the mandibular symphysis, is still visible as a faint ridge in the midline. Like other symphyses in the body, this is a midline articulation where the bones are joined by fibrocartilage, but this articulation fuses together in early childhood.Illustrated Anatomy of the Head and Neck, Fehrenbach and Herring, Elsevier, 2012, p. 59 The word "mandible" derives from the Latin word ''mandibula'', "jawbone" (literally "one used for chewing"), from ''wikt:mandere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mission Valley Formation
The Mission Valley Formation is a marine sandstone geologic formation in the Mission Valley region of southwestern San Diego County in Southern California. Geology The formation's sandstone characteristics are: soft and friable, light olive gray, fine to medium grained, and composed mostly of quartz and potassium feldspar. The Mission Valley Formation thins from the west to the east, with a maximum thickness of . It overlies the Stadium Conglomerate formation and underlies the Pomerado Conglomerate formation. Fossil content It preserves fossils dating back to the Paleogene period of the Cenozoic Era. The formation's rocks can contain a molluscan fauna in the western and central exposures and a land-mammal fauna in the eastern exposures. Mammals Eulipotyphlans Ferae Primatomorphs See also * * * List of fossiliferous stratigraphic units in California * Paleontology in California Paleontology in California refers to paleontologist research occurring within or conduct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carnivoraformes
Carnivoraformes ("carnivoran-like forms") is a clade of Placentalia, placental mammals that includes the modern order Carnivora and its extinct stem-relatives. Classification and phylogeny Classification In 2010 Flynn, Finarelli & Spaulding named a new clade Carnivoraformes within Carnivoramorpha, containing carnivorans and "Miacidae, miacids" but not Viverravidae, viverravids. The authors defined Carnivoraformes as the clade containing Carnivora and all taxa that are more closely related to Carnivora (represented by ''Wolf, Canis lupus'') than to viverravids (represented by ''Viverravus, Viverravus gracilis''). * ''Clade'': Carnivoraformes ** Order: Carnivora (carnivorans) *** Suborder: Caniformia ("dog-like" carnivorans) *** Suborder: Feliformia ("cat-like" carnivorans) ** Family: †Quercygale, Quercygalidae ** (unranked): †''Gracilocyon''/''Oodectes'' clade *** Genus: †''Eogale'' *** Genus: †''Gracilocyon''(Paraphyly, paraphyletic genus) *** Genus: †''Oodectes'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferae
Ferae ( , , "wild beasts") is a mirorder of placental mammalsMalcolm C. McKenna, Susan K. Bell: ''Classification of Mammals: Above the Species Level'' in Columbia University Press, New York (1997), 631 Seiten. that groups together clades Pan-Carnivora and Pholidotamorpha. The Ferae is a sister group to the clade Pan-Euungulata and together they make grandorder Ferungulata. Classification and phylogeny Taxonomy : Phylogeny The phylogenetic relationships of mirorder Ferae are shown in the following cladogram, reconstructed from mitochondrial and nuclear DNA and protein characters, as well as the fossil record.O’Leary, M. A., Bloch JI, Flynn, J. J., Gaudin, T. J., Giallombardo, A., Giannini, N. P., Goldber, S. L, Kraatz, B. P., Luo, Z-X, Jin Meng, Xijun Ni, Novacek, M. J., Perini, F. A., Randall, Z. S., Rougier, G. W., Sargis, E. J., Silcox, M. T., Simmons, N. B., Spaulding, M. Velazco, P. M., Weksler, M., Wible, J. R. Cirranello, A. L. (2013."The Placental Mammal Ancestor an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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