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Dinosaurs Of The Morrison Formation
The Morrison Formation is a distinctive sequence of Upper Jurassic sedimentary rock that is found in the western United States, which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone and limestone and is light grey, greenish gray, or red. Most of the fossils occur in the green siltstone beds and lower sandstones, relics of the rivers and floodplains of the Jurassic period. Fauna comparisons The fauna of Morrison Formation is similar to one in the coeval rocks of Tendaguru Beds (in Tanzania) and Lourinhã Formation in Portugal, mostly with the second. Some genera are shared in Morrison and Lourinhã, such as ''Torvosaurus'', ''Ceratosaurus'', ''Stegosaurus'', ''Dryosaurus'', and ''Allosaurus''.Mateus, O, Walen A, Antunes MT. 2006. The large theropod fauna of the Lourinhã Formation (Portugal) and its similarity to the Morrison Formation, with a description of a new species of Allosaurus. New Mexico Museum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Jurassic
The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987. In European lithostratigraphy, the name "Malm" indicates rocks of Late Jurassic age. In the past, ''Malm'' was also used to indicate the unit of geological time, but this usage is now discouraged to make a clear distinction between lithostratigraphic and geochronologic/chronostratigraphic units. Subdivisions The Late Jurassic is divided into three ages, which correspond with the three (faunal) stages of Upper Jurassic rock: Paleogeography During the Late Jurassic Epoch, Pangaea broke up into two supercontinents, Laurasia to the north, and Gondwana to the south. The result of this break-up was the spawning of the Atlantic Ocean. However, at this time, the Atlantic Ocean was relatively narrow. Life forms of the epoch This epoch is well known for many famous types of dinosau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allosaurus
''Allosaurus'' () is a genus of large carnosaurian theropod dinosaur that lived 155 to 145 million years ago during the Late Jurassic epoch (Kimmeridgian to late Tithonian). The name "''Allosaurus''" means "different lizard" alluding to its unique (at the time of its discovery) concave vertebrae. It is derived from the Greek (') ("different, other") and (') ("lizard / generic reptile"). The first fossil remains that could definitively be ascribed to this genus were described in 1877 by paleontologist Othniel Charles Marsh. As one of the first well-known theropod dinosaurs, it has long attracted attention outside of paleontological circles. ''Allosaurus'' was a large bipedal predator. Its skull was light, robust and equipped with dozens of sharp, serrated teeth. It averaged in length for ''A. fragilis'', with the largest specimens estimated as being long. Relative to the large and powerful hindlimbs, its three-fingered forelimbs were small, and the body was balanced b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drinker Nisti
''Nanosaurus'' ("small or dwarf lizard") is the name given to a genus of neornithischian dinosaur that lived about 155 to 148 million years ago, during the Late Jurassic-age. Its fossils are known from the Morrison Formation of the south-western United States. The type and only species, ''Nanosaurus agilis'', was described and named by Othniel Charles Marsh in 1877. The taxon has a complicated taxonomic history, largely the work of Marsh and Peter M. Galton, involving the genera ''Laosaurus'', ''Hallopus'', ''Drinker'', ''Othnielia'', and ''Othnielosaurus'', the latter three now being considered to be synonyms of ''Nanosaurus''. It had historically been classified as a hypsilophodont or fabrosaur, types of generalized small bipedal herbivore, but more recent research has abandoned these groupings as paraphyletic and ''Nanosaurus'' is today considered a basal member of Neornithischia. Description ''Nanosaurus'' is known from material from all parts of the body, including tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ornithopoda
Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (), that started out as small, bipedal running grazers and grew in size and numbers until they became one of the most successful groups of herbivores in the Cretaceous world, dominating the North American land. Their major evolutionary advantage was the progressive development of a chewing apparatus that became the most sophisticated ever developed by a non-avian dinosaur, rivaling that of modern mammals such as the domestic cow. They reached their apex of diversity and ecological dominance in the hadrosaurids (colloquially known as 'duck-bills'), before they were wiped out by the Cretaceous–Paleogene extinction event along with all other non-avian dinosaurs. Members are known from all seven continents, though they are generally rare in the Southern Hemisphere. History of research In 1870, Thomas Henry Huxley listed Iguanodontidae (coined by Cope a year earlier) as one of his three families of dinosaurs ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mymoorapelta
''Mymoorapelta'' (Meaning "Vannetta Moore and Pete and Marilyn Mygatt's shield" after a combination of the names of the discoverers of the Mygatt-Moore Quarry that fossils were originally collected from, and pɛltə "shield") is a monospecific genus of nodosaurid ankylosaur, a group of heavily armored, herbivorous, quadrupedal dinosaurs, from the Late Jurassic (Kimmeridgian- Tithonian, around 155 to 150 million years ago) Morrison Formation (Brushy Basin Member) of western Colorado and central Utah, USA. Few specimens are known, but the most complete one is the holotype individual from the Mygatt-Moore Quarry that includes many osteoderms, a partial skull, vertebrae, and other bones. It was initially described by James Kirkland and Kenneth Carpenter in 1994. Along with ''Gargoyleosaurus'', it is one of the earliest known nodosaurids. ''Mymoorapleta'' is one of the smaller known nodosaurids, with the estimated length of the largest specimen only reaching . It had a narrow snou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gargoyleosaurus
''Gargoyleosaurus'' (meaning "gargoyle lizard") is one of the earliest ankylosaurs known from reasonably complete fossil remains. The holotype was discovered in 1995 at the Bone Cabin Quarry West locality, in Albany County, Wyoming in exposures of the Upper Jurassic (Kimmeridgian to Tithonian stages) Morrison Formation. The type species, ''G. parkpinorum'' (originally ''G. parkpini'') was described by Ken Carpenter ''et al.'' in 1998. A mounted skeletal reconstruction of ''Gargoyleosaurus parkpinorum'' can be seen at the Denver Museum of Nature and Science and, alongside a couple skeletons of baby ''Stegosaurus'', has been on display there since around 2002. ''Gargoyleosaurus'' was present in stratigraphic zone 2 of the Morrison Formation.Foster, J. (2007). "Appendix." ''Jurassic West: The Dinosaurs of the Morrison Formation and Their World''. Indiana University Press. pp. 327–329. Discovery The holotype specimen of ''Gargoyleosaurus parkpinorum'' was collected by Western P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ankylosauria
Ankylosauria is a group of herbivorous dinosaurs of the order Ornithischia. It includes the great majority of dinosaurs with armor in the form of bony osteoderms, similar to turtles. Ankylosaurs were bulky quadrupeds, with short, powerful limbs. They are known to have first appeared in the Middle Jurassic, and persisted until the end of the Cretaceous Period. The two main families of Ankylosaurs, Nodosauridae and Ankylosauridae are primarily known from the Northern Hemisphere, but the more basal Parankylosauria are known from southern Gondwana during the Cretaceous. Ankylosauria was first named by Henry Fairfield Osborn in 1923.Osborn, H. F. (1923). "Two Lower Cretaceous dinosaurs of Mongolia." ''American Museum Novitates'', 95: 1–1/ref> In the Linnaean classification system, the group is usually considered either a suborder or an infraorder. It is contained within the group Thyreophora, which also includes the stegosaurs, armored dinosaurs known for their combination of plate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcovasaurus
''Alcovasaurus'', alternatively known as ''Miragaia longispinus'', is a genus of herbivorous thyreophoran dinosaur that lived in the Late Jurassic. It was found in the Morrison Formation of Natrona County, Wyoming, United States. The type species is ''Stegosaurus longispinus'', later given the genus ''Alcovasaurus'', and in 2019 recombined as ''Miragaia longispinus''. Discovery and naming In July 1908, Professors William Harlow Reed and A.C. Dart of the University of Wyoming, in the Alcova Quarry in Natrona County, Wyoming, uncovered the skeleton of a stegosaurian. This would be the last major excavation of a dinosaur in which Reed was personally involved. In 1914, the find was named and described as ''Stegosaurus longispinus'' by Charles Whitney Gilmore on the basis of holotype UW 20503 (originally UW D54), a partial postcranial skeleton of an adult individual consisting of forty-two vertebrae, a fragmentary sacrum, two ischia, a portion of one pubis, the right femur, several ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hesperosaurus
''Hesperosaurus'' (meaning "western lizard", from Classical Greek (') "western" and (') "lizard") is an herbivorous stegosaurian dinosaur from the Kimmeridgian epoch of the Jurassic period, approximately 156 million years ago. Fossils of ''Hesperosaurus'' have since 1985 been found in the state of Wyoming and Montana in the United States of America. The type species ''Hesperosaurus mjosi'' was named in 2001. It is from an older part of the Morrison Formation, and so a little older than other Morrison stegosaurs. Several relatively complete skeletons of ''Hesperosaurus'' are known. One specimen preserves the first known impression of the horn sheath of a stegosaurian back plate. ''Hesperosaurus'' was a member of the Stegosauridae, quadrupedal plant-eaters protected by vertical bony plates and spikes. It was closely related to ''Stegosaurus'' and was similar to it in having two rows of, possibly alternating, plates on its back and four spikes on its tail end. The plates on its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stegosauridae
Stegosauridae is a family of thyreophoran dinosaurs (armoured dinosaurs) within the suborder Stegosauria. The clade is defined as all species of dinosaurs more closely related to ''Stegosaurus'' than ''Huayangosaurus''.David B. Weishampel, Peter Dodson, Halszka Osmólska. The ''Dinosauria'' (2nd ed.). Berkeley: University of California Press. The name ‘Stegosauridae’ is thus a stem-based name taken from the well-represented genus – ''Stegosaurus'' (meaning ‘roofed lizard’). Fossil evidence of stegosaurids, dating from the Middle Jurassic through the Early Cretaceous, have been recovered from North America, Eurasia and Africa. The clade Stegosauridae is composed of the genera ''Stegosaurus'', ''Dacentrurus'', '' Miragaia'', ''Loricatosaurus'', and ''Kentrosaurus'', with the last considered to be at the base of the clade. The stegosaurids like all other stegosaurians were quadrupedal herbivores that exhibited the characteristic stegosaurian dorsal dermal plates. These larg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterodontosauridae
Heterodontosauridae is a family of ornithischian dinosaurs that were likely among the most basal (primitive) members of the group. Their phylogenetic placement is uncertain but they are most commonly found to be primitive, outside of the group Genasauria. Although their fossils are relatively rare and their group small in numbers, they have been found on all continents except Australia and Antarctica, with a range spanning the Early Jurassic to the Early Cretaceous. Heterodontosaurids were fox-sized dinosaurs less than in length, including a long tail. They are known mainly for their characteristic teeth, including enlarged canine-like tusks and cheek teeth adapted for chewing, analogous to those of Cretaceous hadrosaurids. Their diet was herbivorous or possibly omnivorous. Description Among heterodontosaurids, only ''Heterodontosaurus'' itself is known from a complete skeleton. Fragmentary skeletal remains of ''Abrictosaurus'' are known but have not been fully described, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
