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Acrotholus Audeti
''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 R ... [...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] |
Colepiocephale Lambei
''Colepiocephale'' (meaning "knucklehead") is a genus of pachycephalosaurid dinosaur from Late Cretaceous (middle Campanian stage) deposits of Alberta, Canada. It was collected from the Foremost Formation (middle Campanian, 80–77.5 ma). The type species, ''C. lambei'', was originally described by Sternberg (in 1945 as ''Stegoceras lambei''C. M. Sternberg. 1945. Pachycephalosauridae proposed for dome-headed dinosaurs, Stegoceras lambei, n. sp., described. Journal of Paleontology 19(5):534-538), and later renamed by Sullivan in 2003. ''C. lambei'' is a domed pachycephalosaur characterized principally by the lack of a lateral and posteriosquamosal shelf, a steeply down-turned parietal, and the presence of two incipient nodes tucked under the posterior margin of the parietosquamosal border. See also * Timeline of pachycephalosaur research This timeline of pachycephalosaur research is a chronological listing of events in the history of paleontology focused on the pachycepha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphaerotholus Goodwini
''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] |
Sphaerotholus Buchholtzae
''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] |
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 synonymized with ''Pachycephalosaurus'', as have the genera ''Stygimoloch'' and ''Dracorex'' in recent studies. Like other pachycephalosaurids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alaskacephale Gangloffi
''Alaskacephale'' was a genus of pachycephalosaurid dinosaur from the Prince Creek Formation, that lived in the early Maastrichtian stages of the Late Cretaceous (around 71 to 69 million years ago). Discovery ''Alaskacephale'' was named by Robert Sullivan in 2006. The genus name refers to Alaska, where the holotype was discovered, combined with the Greek ''kephale'', meaning head. The species name, ''gangloffi'', honors paleontologist Roland Gangloff. The only known specimen of ''A. gangloffi'' is the holotype UAM AK-493-V-001, found in 1999, a nearly complete left squamosal with a characteristic array of polygonal nodes. The dimensions of this bone suggest that ''A. gangloffi'' was about half the size of ''Pachycephalosaurus wyomingensis'' or three quarters the size of ''Prenocephale'', and about the same size as '' Sphaerotholus edmontonensis'' and ''Foraminacephale''. The specimen was previously described by Gangloff ''et al.'' (2005) as an unnamed pachycephalosaurid, possibl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prenocephale Prenes
''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 supratemporal fenestra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amtocephale Gobiensis
''Amtocephale'' (meaning " Amtgai head") is a genus of pachycephalosaurid dinosaur from early Late Cretaceous (Turonian-Santonian stages) deposits of southern Gobi Desert, Mongolia. ''Amtocephale'' is known from the holotype MPC-D 100/1203, a nearly complete frontoparietal dome of a subadult individual. It was collected from the Baynshire Formation at the Amtgai locality. ''Amtocephale'' was first named by Mahito Watabe, Khishigjaw Tsogtbaatar and Robert M. Sullivan in 2011 and the type species is ''Amtocephale gobiensis''. The generic name combines a reference to the Amtgai site with a Greek κεφαλή, ''kephale'', "head". The specific name refers to the provenance from the Gobi. The frontoparietal dome, formed by a fusion of the frontals in front and the parietals in the back, has a length of and a maximal thickness of . The contribution to the dome length of the parietal part is exceptionally large, with a portion of 41%. ''Amtocephale'' was assigned to the Pac ... [...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 dom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tylocephale Gilmorei
''Tylocephale'' (meaning "swollen head", from the Greek ''τυλη'' meaning 'callus' or 'hard swelling' and ''κεφαλη'' meaning 'head') is a genus of pachycephalosaurid dinosaur from the Late Cretaceous period. It was a herbivorous dinosaur, reaching in length and in body mass. It had the tallest dome of any known pachycephalosaur. ''Tylocephale'' lived during the Campanian stage, around 74 million years ago. It was discovered in the Khulsan locality of the Barun Goyot Formation, Mongolia sometime between 1965 and 1971. The type species is ''T. gilmorei'', described by Teresa Maryańska and Osmólska in 1974 based on a partial skull (specimen ZPAL MgD-I/105). Pachycephalosaurids evolved in Asia and then migrated into North America, thus it is likely that ''Tylocephale'' migrated back into Asia. It is closely related to ''Prenocephale''. See also * Timeline of pachycephalosaur research This timeline of pachycephalosaur research is a chronological listing of even ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homalocephale Calathocercos
''Homalocephale'' (from 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 infratemporal fenestrae, and a large, round eye socket. The forehead is notably ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goyocephale Lattimorei
''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 pachyc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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