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Marginocephalia
Marginocephalia (/mär′jə-nō-sə-făl′ē-ən/ Latin: margin-head) is a clade of ornithischian dinosaurs that is characterized by a bony shelf or margin at the back of the skull. These fringes were likely used for display. There are two clades included in Marginocephalia: the thick-skulled Pachycephalosauria and the horned Ceratopsia. All members of Marginocephalia were primarily herbivores. They basally used gastroliths to aid in digestion of tough plant matter until they convergently evolved tooth batteries in Neoceratopsia (or "new Ceratopsia") and Pachycephalosauria. Marginocephalia first evolved in the Jurassic Period and became more common in the Cretaceous. They are basally small facultative quadrupeds while derived members of the group are large obligate quadrupeds. Primitive marginocephalians are found in Asia, but the group migrated upwards into North America. Pachycephalosaurs, or "thick-headed reptiles", have primitive features that include basally small sized bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pachycephalosauria
Pachycephalosauria (; from Greek παχυκεφαλόσαυρος for 'thick headed lizards') is a clade of ornithischian dinosaurs. Along with Ceratopsia, it makes up the clade Marginocephalia. With the exception of two species, most pachycephalosaurs lived during the Late Cretaceous Period, dating between about 85.8 and 65.5 million years ago. They are exclusive to the Northern Hemisphere, all of them being found in North America and Asia. They were all bipedal, herbivorous/omnivorous animals with thick skulls. Skulls can be domed, flat, or wedge-shaped depending on the species, and are all heavily ossified. The domes were often surrounded by nodes and/or spikes. Partial skeletons have been found of several pachycephalosaur species, but to date no complete skeletons have been discovered. Often isolated skull fragments are the only bones that are found. Candidates for the earliest known pachycephalosaur include ''Ferganocephale adenticulatum'' from Middle Jurassic Period strat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stegoceras Validum
''Stegoceras'' is a genus of pachycephalosaurid (dome-headed) dinosaur that lived in what is now North America during the Late Cretaceous period, about 77.5 to 74 million years ago (mya). The first specimens from Alberta, Canada, were described in 1902, and the type species ''Stegoceras validum'' was based on these remains. The generic name means "horn roof", and the specific name means "strong". Several other species have been placed in the genus over the years, but these have since been moved to other genera or deemed junior synonyms. Currently only ''S. validum'' and ''S. novomexicanum'', named in 2011 from fossils found in New Mexico, remain. The validity of the latter species has also been debated. ''Stegoceras'' was a small, bipedal dinosaur about long, and weighed around . The skull was roughly triangular with a short snout, and had a thick, broad, and relatively smooth dome on the top. The back of the skull had a thick "shelf" over the occiput, and it had a thick r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratopsia
Ceratopsia or Ceratopia ( or ; Greek: "horned faces") is a group of herbivorous, beaked dinosaurs that thrived in what are now North America, Europe, and Asia, during the Cretaceous Period, although ancestral forms lived earlier, in the Jurassic. The earliest known ceratopsian, '' Yinlong downsi'', lived between 161.2 and 155.7 million years ago.Holtz, Thomas R. Jr. (2011) ''Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages,'Winter 2010 Appendix./ref> The last ceratopsian species, '' Triceratops prorsus'', became extinct during the Cretaceous–Paleogene extinction event, . ''Triceratops'' is by far the best-known ceratopsian to the general public. It is traditional for ceratopsian genus names to end in "''-ceratops''", although this is not always the case. One of the first named genera was '' Ceratops'' itself, which lent its name to the group, although it is considered a ''nomen dubium'' today as its fossil remains have no distinguishing ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stenopelix
''Stenopelix'' (meaning "narrow pelvis") is a genus of small marginocephalian dinosaur, possibly a basal ceratopsian, from the Early Cretaceous of Germany. It lived in the late Berriasian Stage of the Cretaceous period, approximately 140 myr ago.Holtz, Thomas R. Jr. (2011) ''Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages,'Winter 2010 Appendix./ref> The genus is based on a partial skeleton lacking the skull, and its classification is based on characteristics of the hips. Discovery and species In 1855, in a sandstone quarry near Bückeburg on the Harrl, a fossil was found of a small dinosaur. Most of its bones were in a poor condition and removed on preparation, leaving two sets of hollow impressions on the plate and counterplate. The two plates do not overlap completely. The hollows, serving as a natural mold, have since been used to produce several casts in gypsum and latex to facilitate the study of the specimen. It was originally part of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psittacosaurus
''Psittacosaurus'' ( ; "parrot lizard") is a genus of extinct ceratopsian dinosaur from the Early Cretaceous of what is now Asia, existing between 126 and 101 million years ago. It is notable for being the most species-rich non-avian dinosaur genus. Up to 12 species are known, from across China, Mongolia, Russia, and Thailand. The species of ''Psittacosaurus'' were obligate bipeds at adulthood, with a high skull and a robust beak. One individual was found preserved with long filaments on the tail, similar to those of ''Tianyulong''. ''Psittacosaurus'' probably had complex behaviours, based on the proportions and relative size of the brain. It may have been active for short periods of time during the day and night, and had well-developed senses of smell and vision. ''Psittacosaurus'' was one of the earliest ceratopsians, but closer to ''Triceratops'' than ''Yinlong''. Once in its own family, Psittacosauridae, with other genera like ''Hongshanosaurus'', it is now considered to be s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stygimoloch
''Pachycephalosaurus'' (; meaning "thick-headed lizard", from Greek ''pachys-/'' "thick", ''kephale/'' "head" and ''sauros/'' "lizard") is a genus of pachycephalosaurid dinosaurs. The type species, ''P. wyomingensis'', is the only known species, but some researchers argue that there might be a second species, ''P. spinifer''. It lived during the Late Cretaceous Period (Maastrichtian stage) of what is now North America. Remains have been excavated in Montana, South Dakota, Wyoming, and Alberta. It was a herbivorous creature which is primarily known from a single skull and a few extremely thick skull roofs, at 22 centimetres (9 inches) thick. More complete fossils have been found in recent years. ''Pachycephalosaurus'' was among the last non-avian dinosaurs before the Cretaceous–Paleogene extinction event. The genus ''Tylosteus'' has been synonymized with ''Pachycephalosaurus'', as have the genera ''Stygimoloch'' and ''Dracorex'' in recent studies. Like other pachycephalosaurid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protoceratops
''Protoceratops'' (; ) is a genus of small protoceratopsid dinosaurs that lived in Asia during the Late Cretaceous, around 75 to 71 million years ago. The genus ''Protoceratops'' includes two species: ''P. andrewsi'' and the larger ''P. hellenikorhinus''. The former was described in 1923 with fossils from the Mongolian Djadokhta Formation, and the latter in 2001 with fossils from the Chinese Bayan Mandahu Formation. ''Protoceratops'' was initially believed to be an ancestor of ankylosaurians and larger ceratopsians, such as ''Triceratops'' and relatives, until the discoveries of other protoceratopsids. Populations of ''P. andrewsi'' may have evolved into ''Bagaceratops'' through anagenesis. ''Protoceratops'' were small ceratopsians, about long and in body mass. While adults were largely quadrupedal, juveniles had the capacity to walk around Facultative bipedalism, bipedally if necessary. They were characterized by a proportionally large skull, short and stiff neck, and neck fri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pachycephalosaurus Wyomingensis
''Pachycephalosaurus'' (; meaning "thick-headed lizard", from Greek ''pachys-/'' "thick", ''kephale/'' "head" and ''sauros/'' "lizard") is a genus of pachycephalosaurid dinosaurs. The type species, ''P. wyomingensis'', is the only known species, but some researchers argue that there might be a second species, ''P. spinifer''. It lived during the Late Cretaceous Period (Maastrichtian stage) of what is now North America. Remains have been excavated in Montana, South Dakota, Wyoming, and Alberta. It was a herbivorous creature which is primarily known from a single skull and a few extremely thick skull roofs, at 22 centimetres (9 inches) thick. More complete fossils have been found in recent years. ''Pachycephalosaurus'' was among the last non-avian dinosaurs before the Cretaceous–Paleogene extinction event. The genus ''Tylosteus'' has been Synonym (taxonomy), synonymized with ''Pachycephalosaurus'', as have the genera ''Stygimoloch'' and ''Dracorex'' in recent studies. Like other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ornithischia
Ornithischia () is an extinct order of mainly herbivorous dinosaurs characterized by a pelvic structure superficially similar to that of birds. The name ''Ornithischia'', or "bird-hipped", reflects this similarity and is derived from the Greek stem ' (), meaning "of a bird", and ' (), plural ', meaning "hip joint". However, birds are only distantly related to this group as birds are theropod dinosaurs. Ornithischians with well known anatomical adaptations include the ceratopsians or "horn-faced" dinosaurs (e.g. ''Triceratops''), the pachycephalosaurs or "thick-headed" dinosaurs, the armored dinosaurs ( Thyreophora) such as stegosaurs and ankylosaurs, and the ornithopods. There is strong evidence that certain groups of ornithischians lived in herds, often segregated by age group, with juveniles forming their own flocks separate from adults. Some were at least partially covered in filamentous (hair- or feather- like) pelts, and there is much debate over whether these filaments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triceratops Horridus
''Triceratops'' ( ; ) is a genus of herbivorous chasmosaurine ceratopsid dinosaur that first appeared during the late Maastrichtian stage of the Late Cretaceous period, about 68 million years ago in what is now North America. It is one of the last-known non-avian dinosaur genera, and became extinct in the Cretaceous–Paleogene extinction event 66 million years ago. The name ''Triceratops'', which literally means 'three-horned face', is derived from the Greek words () meaning 'three', () meaning 'horn', and () meaning 'face'. Bearing a large bony frill, three horns on the skull, and a large four-legged body, exhibiting convergent evolution with rhinoceroses and bovines, ''Triceratops'' is one of the most recognizable of all dinosaurs and the most well-known ceratopsid. It was also one of the largest, up to long and in body mass. It shared the landscape with and was most likely preyed upon by ''Tyrannosaurus'', though it is less certain that two adults did bat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triceratops
''Triceratops'' ( ; ) is a genus of herbivorous chasmosaurine ceratopsid dinosaur that first appeared during the late Maastrichtian stage of the Late Cretaceous period, about 68 million years ago in what is now North America. It is one of the last-known non-avian dinosaur genera, and became extinct in the Cretaceous–Paleogene extinction event 66 million years ago. The name ''Triceratops'', which literally means 'three-horned face', is derived from the Greek words () meaning 'three', () meaning 'horn', and () meaning 'face'. Bearing a large bony frill, three horns on the skull, and a large four-legged body, exhibiting convergent evolution with rhinoceroses and bovines, ''Triceratops'' is one of the most recognizable of all dinosaurs and the most well-known ceratopsid. It was also one of the largest, up to long and in body mass. It shared the landscape with and was most likely preyed upon by ''Tyrannosaurus'', though it is less certain that two adults did ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Styracosaurus
''Styracosaurus'' ( ; meaning "spiked lizard" from the Ancient Greek / "spike at the butt-end of a spear-shaft" and / "lizard") is a genus of herbivorous ceratopsian dinosaur from the Cretaceous Period (Campanian stage), about 75.5 to 74.5 million years ago. It had four to six long parietal spikes extending from its neck frill, a smaller jugal horn on each of its cheeks, and a single horn protruding from its nose, which may have been up to long and wide. The function or functions of the horns and frills have been debated for many years. ''Styracosaurus'' was a relatively large dinosaur, reaching lengths of and weighing about . It stood about tall. ''Styracosaurus'' possessed four short legs and a bulky body. Its tail was rather short. The skull had a beak and shearing cheek teeth arranged in continuous dental batteries, suggesting that the animal sliced up plants. Like other ceratopsians, this dinosaur may have been a herd animal, travelling in large groups, as s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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