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Pachycephalosaur
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 Peri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stegoceras
''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] |
Pachycephalosaurus
''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 pachycephalosa ... [...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] |
Acrotholus
''Acrotholus'' (Greek for "highest dome"- akros meaning highest and tholos meaning dome) is an extinct genus of pachycephalosaur dinosaur that lived during the Santonian of the late Cretaceous, in the Milk River Formation of Canada. The type species, ''A. audeti'', was named after Roy Audet allowing access to his ranch leading to the discovery of the species. The discovery of this specimen lead to several new revelations in the fossil records questioning the preservation of small-bodied organisms along with the evolution of early pachycephalosaurs. The iconic cranial dome found on ''Acrotholus'' makes it one of the earliest indisputable known members of the pachycephalosaur family. Like others of its clade, ''Acrotholus'' was a bipedal herbivore characterized by a dome-shaped head. The dome had often been associated with intra-species combat though exact method of contact have been debated. History of discovery The holotype was found in the Deadhorse Coulee Member of the Milk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinocephale
''Sinocephale'' (meaning "Chinese head") is a genus of pachycephalosaurid dinosaur that lived in Inner Mongolia, China during the Cretaceous period. The only species, ''Sinocephale bexelli'', was originally named as a species of the genus ''Troodon'' in 1953, and later transferred to the genus ''Stegoceras''. After decades of being considered dubious, it was re-evaluated in 2021 and recognized as a valid taxon, being given a unique generic name. The original holotype was lost, with modern research conducted using rediscovered plaster casts. Scant material makes for limited knowledge of its life appearance, but it is distinguished by an embayment on the back of the domed skull, which would give it a heart shape as seen from above. It is potentially the oldest known pachycephalosaurid and falls within the subset of the family called Pachycephalosaurinae, related to animals such as ''Stegoceras''. The geologic context of the species has been historically unclear but it is currently t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foraminacephale
''Foraminacephale'' (meaning "foramina head") is a genus of pachycephalosaurid dinosaur from Late Cretaceous (Campanian stage) deposits of Canada. Description ''Foraminacephale'', as a pachycephalosaurid, was a small, bipedal herbivore with a thickened dome on its skull. In 2016, Gregory S. Paul estimated its length at , its weight at . In ''Foraminacephale'', the top surface of the dome is punctuated by many small pits, the eponymous foramina; the dome itself consists of a large, central lobe with a sloped frontal half, and two smaller lateral lobes at the front. The squamosal bone forms a tall bar of completely smooth bone underneath the dome, save for six bony nodes that line the bottom edge of the dome and an additional "corner" node just below. These features differentiate ''Foraminacephale'' from all other pachycephalosaurids. Unlike ''Stegoceras'', '' Hanssuesia'', and '' Colepiocephale'', the parietal bone of ''Foraminacephale'' (which constitutes the back part of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Goyocephale
''Goyocephale'' is an extinct genus of pachycephalosaurian ornithischian that lived in Mongolia during the Late Cretaceous about 76 million years ago. It was first described in 1982 by Altangerel Perle, Teresa Maryańska and Halszka Osmólska for a disarticulated skeleton with most of a skull, part of the forelimb and hindlimb, some of the pelvic girdle, and some vertebrae. Perle ''et al.'' named the remains ''Goyocephale lattimorei'', from the Mongolian гоё (''goyo''), meaning "decorated", and the Ancient Greek κεφαλή (''kephale''), for head. The species name honours Owen Lattimore. Description ''Goyocephale'' is known from a partial skull, including both mandibles, the skull roof, part of the occiput, part of the braincase region, the posterior skull, the premaxilla, and the maxilla. The posterior edge of the skull roof, at the edge of the squamosal bones, has many small bony bumps, which would have been the base of small horns in life. A feature shared with pac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphaerotholus
''Sphaerotholus'' is a genus of pachycephalosaurid dinosaur from the Upper Cretaceous of the western United States and Canada. To date, three species have been described: the type species, ''S. goodwini'', from the Den-na-zin Member of the Kirtland Formation (Late Campanian) of San Juan County, New Mexico, USA; ''S. buchholtzae'', from the Hell Creek Formation (Late Maastrichtian) of western Carter County, Montana, USA and the Frenchman Formation of Saskatchewan, Canada; and ''S. edmontonensis'', from the Horseshoe Canyon Formation of Alberta, Canada. History of discovery The etymology of ''Sphaerotholus'' is a combination of the Greek ''sphaira'', meaning "ball", and ''tholos'', meaning "dome", and is a reference to the characteristically dome-shaped pachycephalosaurian skull. The survival of ''Sphaerotholus'' from the Campanian of New Mexico to the end of the Maastrichtian of Montana demonstrates that this taxon had both a relatively long duration (approximately 7-8 mil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravitholus
''Gravitholus'' (meaning 'heavy dome') was a genus of pachycephalosaurid dinosaur from the late Cretaceous period (Campanian stage, around 75 million years ago). It was a pachycephalosaur, and like other pachycephalosaurids the skull roof formed a thick dome made of dense bone, which may have been used in head-butting contests over mates or territory. It lived in what is now Alberta, Canada, and was described in 1979 by W. P. Wall and Peter Galton. The type species is ''Gravitholus albertae''. There is some debate amongst paleontologists as to whether the animal represents a distinct genus, or if it may be synonymous with ''Stegoceras''. Recent publications indicate it may be a valid genus. ''Gravitholus'' is one of several pachycephalosaurids known from Dinosaur Park, including '' Stegoceras validum'', ''Hanssuesia sternbergi'', and '' Foraminacephale brevis''. It is unclear whether all of these species would have lived in the area at the same time. A 2020 CSVP abstract found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homalocephale
''Homalocephale'' (from Ancient Greek, Greek ὁμαλός, ''homalos'', "even", and κεφαλή, ''kephalē'', "head") is a genus of pachycephalosaurid dinosaur that lived during the Late Cretaceous period of what is now the Nemegt Formation, Mongolia, about 70 million years ago. The genus was described in 1974 by Halszka Osmólska and Teresa Maryańska, and consists of a single species, ''H. calathocercos''. Though ''Homalocephale'' has been regarded as a synonym (and juvenile form) of ''Prenocephale'', juvenile specimens of the latter indicate that they were distinct. ''Homalocephale'' was long and possibly herbivorous. Discovery The type species, ''H. calathocercos'', was described from an incomplete skull and postcranial material (holotype MPC-D 100/1201) from the Nemegt locality of the Nemegt Formation. The specimen has large openings on the top of the skull, a distinct frontoparietal suture, low and long temporal fenestra, infratemporal fenestrae, and a large, round eye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prenocephale
''Prenocephale'' (meaning "sloping head") is a genus of small pachycephalosaurid dinosaur from the Late Cretaceous Nemegt Formation of Mongolia. It was similar in many ways to its close relative, '' Homalocephale''. Description Adult ''Prenocephale'' measured in length and in body mass. Unlike the flattened wedge-shaped skull of ''Homalocephale'' (a possible juvenile trait also potentially seen in early growth stages of ''Pachycephalosaurus''), the head of ''Prenocephale'' was rounded and sloping. The dome had a row of small bony spikes and bumps. Like some other pachycephalosaurs, ''Prenocephale'' is known only from skulls and a few other small bones. For this reason, reconstructions usually depict ''Prenocephale'' as sharing the basic body plan common to all of the other Pachycephalosauria: a stout body with a short, thick neck, short forelimbs and tall hind legs. The head of ''Prenocephale'' was comparable to that of ''Stegoceras'', albeit with closed supra temporal fenes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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