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Orodromeus Makelai
''Orodromeus'' (meaning "Mountain Runner") is a genus of herbivorous orodromine thescelosaurid dinosaur from the Late Cretaceous of North America. Only one species is known, the type species ''Orodromeus makelai''. Discovery and naming The remains of ''Orodromeus'' were discovered by Robert Makela during the excavation in Teton County, Montana, of the ''Egg Mountain'' brooding colony of a much larger relative, ''Maiasaura''. The type species, ''Orodromeus makelai'', was named and shortly described by Jack Horner and David B. Weishampel in 1988. The generic name is derived from Greek ὄρος, ''oros'', "mountain", in reference to the Egg Mountain site, and δρομεύς, ''dromeus'', "runner", referring to the cursorial habits of the animal. The specific name honoured the late Makela.Horner, J. and Weishampel, D., 1988, "A comparative embryological study of two ornithischian dinosaurs", ''Nature'' (London), 332(No. 6161): 256-257 (1988) The holotype specimen, MOR 294, was fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia and Ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Name (zoology)
In zoological nomenclature, the specific name (also specific epithet or species epithet) is the second part (the second name) within the scientific name of a species (a binomen). The first part of the name of a species is the name of the genus or the generic name. The rules and regulations governing the giving of a new species name are explained in the article species description. For example, the scientific name for humans is ''Homo sapiens'', which is the species name, consisting of two names: ''Homo'' is the " generic name" (the name of the genus) and ''sapiens'' is the "specific name". Historically, ''specific name'' referred to the combination of what are now called the generic and specific names. Carl Linnaeus, who formalized binomial nomenclature, made explicit distinctions between specific, generic, and trivial names. The generic name was that of the genus, the first in the binomial, the trivial name was the second name in the binomial, and the specific the proper term for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postorbital
The ''postorbital'' is one of the bones in vertebrate skulls which forms a portion of the dermal skull roof and, sometimes, a ring about the orbit. Generally, it is located behind the postfrontal and posteriorly to the orbital fenestra. In some vertebrates, the postorbital is fused with the postfrontal to create a postorbitofrontal. Birds have a separate postorbital as an embryo, but the bone fuses with the frontal Front may refer to: Arts, entertainment, and media Films * ''The Front'' (1943 film), a 1943 Soviet drama film * ''The Front'', 1976 film Music * The Front (band), an American rock band signed to Columbia Records and active in the 1980s and e ... before it hatches. References * Roemer, A. S. 1956. ''Osteology of the Reptiles''. University of Chicago Press. 772 pp. Skull {{Vertebrate anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palpebral
An eyelid is a thin fold of skin that covers and protects an eye. The levator palpebrae superioris muscle retracts the eyelid, exposing the cornea to the outside, giving vision. This can be either voluntarily or involuntarily. The human eyelid features a row of eyelashes along the eyelid margin, which serve to heighten the protection of the eye from dust and foreign debris, as well as from perspiration. "Palpebral" (and "blepharal") means relating to the eyelids. Its key function is to regularly spread the tears and other secretions on the eye surface to keep it moist, since the cornea must be continuously moist. They keep the eyes from drying out when asleep. Moreover, the blink reflex protects the eye from foreign bodies. The appearance of the human upper eyelid often varies between different populations. The prevalence of an epicanthic fold covering the inner corner of the eye account for the majority of East Asian and Southeast Asian populations, and is also found in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orodromeus Fossil
''Orodromeus'' (meaning "Mountain Runner") is a genus of herbivorous orodromine thescelosaurid dinosaur from the Late Cretaceous of North America. Only one species is known, the type species ''Orodromeus makelai''. Discovery and naming The remains of ''Orodromeus'' were discovered by Robert Makela during the excavation in Teton County, Montana, of the ''Egg Mountain'' brooding colony of a much larger relative, ''Maiasaura''. The type species, ''Orodromeus makelai'', was named and shortly described by Jack Horner and David B. Weishampel in 1988. The generic name is derived from Greek ὄρος, ''oros'', "mountain", in reference to the Egg Mountain site, and δρομεύς, ''dromeus'', "runner", referring to the cursorial habits of the animal. The specific name honoured the late Makela.Horner, J. and Weishampel, D., 1988, "A comparative embryological study of two ornithischian dinosaurs", ''Nature'' (London), 332(No. 6161): 256-257 (1988) The holotype specimen, MOR 294, was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Einiosaurus
''Einiosaurus'' is a genus of herbivorous centrosaurine ceratopsian dinosaur from the Upper Cretaceous (Campanian stage) of northwestern Montana. The name means 'buffalo lizard', in a combination of Blackfeet Indian ''eini'' and Latinized Ancient Greek ''sauros''; the specific name (''procurvicornis'') means 'with a forward-curving horn' in Latin. ''Einiosaurus'' is medium-sized with an estimated body length at . History of discovery The Landslide Butte expeditions ''Einiosaurus'' is an exclusively Montanan dinosaur, and all of its known remains are currently held at the Museum of the Rockies in Bozeman, Montana. At least fifteen individuals of varying ages are represented by three adult skulls and hundreds of other bones from two low-diversity, monospecific (one species) bonebeds, which were discovered by Jack Horner in 1985 and excavated from 1985 to 1989 by Museum of the Rockies field crews. Horner had not been searching for horned dinosaurs. In the spring of 1985 he had b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daspletosaurus
''Daspletosaurus'' ( ; meaning "frightful lizard") is a genus of tyrannosaurid dinosaur that lived in Laramidia between about 79.5 and 74 million years ago, during the Late Cretaceous Period. The genus ''Daspletosaurus'' contains three species. Fossils of the earlier type species, ''D. torosus'', have been found in Alberta, and fossils of a later second species, ''D. wilsoni,'' and third species, ''D. horneri'', have been found only in Montana. A possible fourth species, also from Alberta, awaits formal identification. The taxon ''Thanatotheristes'' has been suggested to represent a species of ''Daspletosaurus'', ''D. degrootorum'', but this has not been widely supported. ''Daspletosaurus'' is closely related to the much larger and more recent tyrannosaurid ''Tyrannosaurus rex''. Like most tyrannosaurids, ''Daspletosaurus'' was a multi-tonne bipedal predator equipped with dozens of large, sharp teeth. ''Daspletosaurus'' had the small forelimbs typical of tyrannosaurids, although ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stenonychosaurus
''Stenonychosaurus'' (meaning "narrow claw lizard") is a genus of troodontid dinosaur from the Late Cretaceous Dinosaur Park Formation of Alberta, Canada, as well as possibly the Two Medicine Formation. The type and only species, ''S. inequalis'', was named by Charles Mortram Sternberg in 1932, based on a foot, fragments of a hand, and some caudal vertebrae from the Late Cretaceous of Alberta. ''S. inequalis'' was reassigned in 1987 by Phil Currie to the genus ''Troodon'', which was reverted by the recognition of ''Stenonychosaurus'' as a separate genus from the possibly dubious ''Troodon'' in 2017 by Evans ''et al.'' and also later in the same year by Van der Reest and Currie. History of discovery The first specimens currently assigned to ''Troodon'' that were not teeth were both found by Sternberg in 1928, in the Dinosaur Park Formation of Alberta. The first was named ''Stenonychosaurus inequalis'' by Sternberg in 1932, based on a foot, fragments of a hand, and some tail verte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Troodontidae
Troodontidae is a clade of bird-like theropod dinosaurs. During most of the 20th century, troodontid fossils were few and incomplete and they have therefore been allied, at various times, with many dinosaurian lineages. More recent fossil discoveries of complete and articulated specimens (including specimens which preserve feathers, eggs, embryos, and complete juveniles), have helped to increase understanding about this group. Anatomical studies, particularly studies of the most primitive troodontids, like ''Sinovenator'', demonstrate striking anatomical similarities with '' Archaeopteryx'' and primitive dromaeosaurids, and demonstrate that they are relatives comprising a clade called Paraves. Description Troodontids are a group of small, bird-like, gracile maniraptorans. All troodontids have unique features of the skull, such as large numbers of closely spaced teeth in the lower jaw. Troodontids have sickle-claws and raptorial hands, and some of the highest non-avian enceph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryo
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm cell. The resulting fusion of these two cells produces a single-celled zygote that undergoes many cell divisions that produce cells known as blastomeres. The blastomeres are arranged as a solid ball that when reaching a certain size, called a morula, takes in fluid to create a cavity called a blastocoel. The structure is then termed a blastula, or a blastocyst in mammals. The mammalian blastocyst hatches before implantating into the endometrial lining of the womb. Once implanted the embryo will continue its development through the next stages of gastrulation, neurulation, and organogenesis. Gastrulation is the formation of the three germ layers that will form all of the different parts of the body. Neurulation forms the nervous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paratype
In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype nor a syntype). Often there is more than one paratype. Paratypes are usually held in museum research collections. The exact meaning of the term ''paratype'' when it is used in zoology is not the same as the meaning when it is used in botany. In both cases however, this term is used in conjunction with ''holotype''. Zoology In zoological nomenclature, a paratype is officially defined as "Each specimen of a type series other than the holotype.", ''International Code of Zoological Nomenclature'' In turn, this definition relies on the definition of a "type series". A type series is the material (specimens of organisms) that was cited in the original publication of the new species or subspecies, and was not excluded from being type material by the author (th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Million Years Ago
The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds. Usage Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago). Together they make a reference system, one to a quantity, the other to a particular place in a year numbering system that is ''time before the present''. Myr is deprecated in geology, but in astronomy ''Myr'' is standard. Where "myr" ''is'' seen in geology it is usually "Myr" (a unit of mega-years). In astronomy it is usually "Myr" (Million years). Debate In geology a debate remains open concerning the use of ''Myr'' (duration) plus ''Ma'' (million years ago) versus using only the term ''Ma''. In either case the term '' Ma'' is used in geology literature conforming to ISO 31-1 (now ISO 80000-3) and NIST 811 recommended practices. Traditional style geology literature is written The "ago" is implied, so that any such year number "X Ma" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
