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Dinosaurs Of The Morrison Formation
The Morrison Formation is a distinctive sequence of Late Jurassic, 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, Jurassic period. Fauna comparisons The fauna of Morrison Formation is similar to one in the coeval rocks of Tendaguru Formation, 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 sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Jurassic
The Late Jurassic is the third Epoch (geology), epoch of the Jurassic Period, and it spans the geologic time scale, geologic time from 161.5 ± 1.0 to 143.1 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic stratum, 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 emergence of the Atlantic Ocean, which initially was relatively narrow. Life forms This epoch is well known for many famous types of d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allosaurus
''Allosaurus'' ( ) is an extinct genus of theropod dinosaur that lived 155 to 145 million years ago during the Late Jurassic period ( Kimmeridgian to late Tithonian ages). The first fossil remains that could definitively be ascribed to this genus were described in 1877 by Othniel C. Marsh. The name "''Allosaurus''" means "different lizard", alluding to its lightweight , which Marsh believed were unique. The genus has a very complicated taxonomy and includes at least three valid species, the best known of which is ''A. fragilis''. The bulk of ''Allosaurus'' remains come from North America's Morrison Formation, with material also known from the Alcobaça Formation and Lourinhã Formation in Portugal. It was known for over half of the 20th century as '' Antrodemus'', but a study of the abundant remains from the Cleveland-Lloyd Dinosaur Quarry returned the name "''Allosaurus''" to prominence. As one of the first well-known theropod dinosaurs, it has long attracted attention ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drinker Nisti
''Nanosaurus'' ("small or dwarf lizard") is an extinct genus of neornithischian dinosaur that lived about 155 to 148 million years ago, during the Late Jurassic in North America. 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. History and taxonomy Marsh's original groundwork ''Nanosaurus'' has had a long and compl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypsilophodontidae
Hypsilophodontidae (or Hypsilophodontia) is a traditionally used family (biology), family of ornithopod dinosaurs, generally considered invalid today. It historically included many small bodied bipedal neornithischian taxa from around the world, and spanning from the Middle Jurassic until the Late Cretaceous. This inclusive status was supported by some phylogenetic analyses from the 1990s and mid 2000s, although there have also been many finding that the family is an unnatural grouping which should only include the type genus, ''Hypsilophodon'', with the other genera being within clades like Thescelosauridae and Elasmaria. A 2014 analysis by Norman recovered a grouping of ''Hypsilophodon'', Rhabdodontidae and ''Tenontosaurus'', which he referred to as Hypsilophodontia. That clade is formally defined in the ''PhyloCode'' as "the smallest clade within Ornithopoda containing ''Hypsilophodon foxii'' and ''Tenontosaurus tilletti'' provided it does not include ''Iguanodon bernissartensis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ornithopoda
Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (). They represent one of the most successful groups of herbivorous dinosaurs during the Cretaceous. The most primitive members of the group were bipedal and relatively small-sized, while advanced members of the subgroup Iguanodontia became quadrupedal and developed large body size. 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 worldwide. History of research In 1870, Thomas Henry Huxley listed Iguanodontidae (coined by Edward Drinker Cope a year earlier) as one of his three famil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mymoorapelta
''Mymoorapelta'' (Meaning "Shield from the Mygatt-Moore Quarry" after a combination of the names of the discoverers of the Mygatt-Moore Quarry that fossils were originally collected from, and the Greek word πέλτα, meaning "shield") is a Nodosauridae, nodosaurid ankylosaur from the Late Jurassic (Kimmeridgian-Tithonian, around 155 to 150 million years ago) Morrison Formation (Brushy Basin Member) of western Colorado and central Utah, United States, USA. The animal is known from a single species, ''Mymoorapelta maysi'', and few specimens are known. The most complete specimen is the holotype individual from the Mygatt-Moore Quarry, which includes , a partial , , and other bones. It was initially described by James Kirkland (paleontologist), James Kirkland and Kenneth Carpenter in 1994. Along with ''Gargoyleosaurus'', it is one of the earliest known nodosaurids. ''Mymoorapelta'' is one of the smaller known nodosaurids, with the estimated length of the largest specimen only reach ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ankylosauria
Ankylosauria is a group of herbivorous dinosaurs of the clade 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 North Africa during the Middle Jurassic, and persisted until the end of the Late Cretaceous. The two main families of ankylosaurians, Nodosauridae and Ankylosauridae primarily originated from the Northern Hemisphere (North America, Europe and Asia), but the more basal Parankylosauria originated from southern Gondwana (South America, Australia and Antarctica) 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcovasaurus
''Alcovasaurus'' is an extinct genus of herbivorous stegosaurian dinosaurs that lived in the Late Jurassic. It was found in the Morrison Formation of Natrona County, Wyoming, Natrona County, Wyoming, United States. The genus contains a monotypic taxon, single species, ''Alcovasaurus longispinus'', originally assigned to the genus ''Stegosaurus''. It is likely a member of the Dacentrurinae, and has been referred to the genus ''Miragaia longicollum, Miragaia'' by some authors. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hesperosaurus
''Hesperosaurus'' (meaning "western lizard", from Classical Greek (') "western" and (') "lizard") is a herbivorous stegosaurian dinosaur from the Kimmeridgian age of the Jurassic period, approximately 156 million years ago. Fossils of ''Hesperosaurus'' have been found in the state of Wyoming and Montana in the United States of America since 1985. 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 back ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stegosauridae
Stegosauria is a group of herbivorous ornithischian dinosaurs that lived during the Jurassic and early Cretaceous periods. Stegosaurian fossils have been found mostly in the Northern Hemisphere (North America, Europe and Asia), Africa and South America. Their geographical origins are unclear; the earliest unequivocal stegosaurian, '' Bashanosaurus primitivus'', was found in the Bathonian Shaximiao Formation of China. Stegosaurians were armored dinosaurs (thyreophorans). Originally, they did not differ much from more primitive members of that group, being small, low-slung, running animals protected by armored scutes. An early evolutionary innovation was the development of spikes as defensive weapons. Later species, belonging to a subgroup called the Stegosauridae, became larger, and developed long hindlimbs that no longer allowed them to run. This increased the importance of active defence by the thagomizer, which could ward off even large predators because the tail was in a hig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterodontosauridae
Heterodontosauridae is a family (biology), family of ornithischian dinosaurs that were likely among the most Basal (phylogenetics), basal (primitive) members of the group. Their phylogenetic placement is uncertain but they are most commonly found 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 (continent), 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 (tooth), canine-like tusks and cheek teeth adapted for chewing, Analogy (biology), analogous to those of Cretaceous hadrosaurids. Their diet was herbivore, herbivorous or possibly omnivore, omnivorous. Description Among heterodontosaurids, only ''Heterodontosaurus'' itself is known from a complete ske ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
