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Acristavus
''Acristavus'' (meaning "non-crested grandfather") is a genus of saurolophine dinosaur. Fossils have been found from the Campanian Two Medicine Formation in Montana and Wahweap Formation in Utah, United States. The type species ''A. gagslarsoni'' was named in 2011. Unlike nearly all hadrosaurids except ''Edmontosaurus'', ''Acristavus'' lacked ornamentation on its skull. The discovery of ''Acristavus'' is paleontologically significant because it supports the position that the ancestor of all hadrosaurids did not possess cranial ornamentation, and that ornamentation was an adaptation that later arose interdependently in the subfamilies Saurolophinae and Lambeosaurinae. It is closely related to '' Brachylophosaurus'' and '' Maiasaura'', and was assigned to a new clade called Brachylophosaurini. Discovery and occurrence left, Skull The holotype specimen of ''Acristavus'', MOR 1155, was recovered at the Two Medicine Formation, in Teton County, Montana. The specimen was collect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acristavus Gagslarsoni
''Acristavus'' (meaning "non-crested grandfather") is a genus of saurolophine dinosaur. Fossils have been found from the Campanian Two Medicine Formation in Montana and Wahweap Formation in Utah, United States. The type species ''A. gagslarsoni'' was named in 2011. Unlike nearly all hadrosaurids except ''Edmontosaurus'', ''Acristavus'' lacked ornamentation on its skull. The discovery of ''Acristavus'' is paleontologically significant because it supports the position that the ancestor of all hadrosaurids did not possess cranial ornamentation, and that ornamentation was an adaptation that later arose interdependently in the subfamilies Saurolophinae and Lambeosaurinae. It is closely related to ''Brachylophosaurus'' and ''Maiasaura'', and was assigned to a new clade called Brachylophosaurini. Discovery and occurrence left, Skull The holotype specimen of ''Acristavus'', MOR 1155, was recovered at the Two Medicine Formation, in Teton County, Montana. The specimen was collected in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wahweap Formation
The Wahweap Formation of the Grand Staircase–Escalante National Monument is a geological formation in southern Utah and northern Arizona, around the Lake Powell region, whose strata date back to the Late Cretaceous (Campanian stage). Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, North America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 574–588. . Age The Wahweap formation is divided into four members, which are listed below with their respective ages: * Last Chance Creek Member: 82.17-81.55 Ma * Reynolds Point Member: 81.55-80.61 Ma * Coyote Point Member: 80.61-79 Ma * Pardner Canyon Member: 79-77.29 Ma Paleobiota Invertebrates The Wahweap Formation shows a substantial amount of invertebrate activity ranging from fossilized insect burrows in petrified logs to var ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachylophosaurini
Brachylophosaurini is a tribe of saurolophine hadrosaurs with known material being from N. America and potentially Asia. It contains at least four taxa; ''Acristavus'' (from Montana and Utah), ''Brachylophosaurus'' (from Montana and Alberta), ''Maiasaura'' (also from Montana), and ''Probrachylophosaurus'' (also from Montana). A hadrosaur from the Amur river, ''Wulagasaurus'', might be a member of this tribe, but this is disputed. The group was defined by Terry A. Gates and colleagues in 2011.http://www.ivpp.cas.cn/cbw/gjzdwxb/xbwzxz/201204/P020120423369434645647.pdf The clade Brachylophosaurini was defined as "Hadrosaurine ornithopods more closely related to ''Brachylophosaurus'', ''Maiasaura'', or ''Acristavus'' than to ''Gryposaurus'' or ''Saurolophus''". See also * Timeline of hadrosaur research A timeline is a display of a list of events in chronological order. It is typically a graphic design showing a long bar labelled with dates paralleling it, and usually contem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maiasaura
''Maiasaura'' (from the Greek ''μαῖα'', meaning "good mother" and ''σαύρα'', the feminine form of ''saurus'', meaning "reptile") is a large herbivorous saurolophine hadrosaurid ("duck-billed") dinosaur genus that lived in the area currently covered by the state of Montana and the province of Alberta, Canada in the Upper Cretaceous Period (mid to late Campanian), about 76.7 million years ago.Horner, J. R., Schmitt, J. G., Jackson, F., & Hanna, R. (2001). Bones and rocks of the Upper Cretaceous Two Medicine-Judith River clastic wedge complex, Montana. In Field trip guidebook, Society of Vertebrate Paleontology 61st Annual Meeting: Mesozoic and Cenozoic Paleontology in the Western Plains and Rocky Mountains. Museum of the Rockies Occasional Paper (Vol. 3, pp. 3-14). The first remains of ''Maiasaura'' were discovered in 1978 by Bynum, Montana resident Laurie Trexler. The genus was named in 1979. The name refers to the find of nests with eggs, embryos and young animals, in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachylophosaurus
''Brachylophosaurus'' ( or ; meaning "short-crested lizard", Greek ''brachys'' = short + ''lophos'' = crest + ''sauros'' = lizard, referring to its small crest) was a mid-sized member of the hadrosaurid family of dinosaurs. It is known from several skeletons and bonebed material from the Judith River Formation of Montana, the Wahweap Formation of Utah and the Oldman Formation of Alberta, living about 81-76.7 million years ago. Discovery and later finds ''Brachylophosaurus'' was first named and described by Charles Mortram Sternberg in 1953 for a skull and partial skeleton, holotype NMC 8893, which he had found in 1936 near Steveville in Alberta, and which was at first thought to belong to ''Gryposaurus'' (or ''Kritosaurus'' as it was known at the time). The type species is ''Brachylophosaurus canadensis''. The generic name is derived from Greek βραχύς, ''brachys'', "short", and λόφος, ''lophos'', "crest of a helmet". The specific name refers to the provenanc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saurolophidae
Hadrosaurids (), or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which includes genera such as ''Edmontosaurus'' and ''Parasaurolophus'', was a common group of herbivores during the Late Cretaceous Period. Hadrosaurids are descendants of the Upper Jurassic/Lower Cretaceous iguanodontian dinosaurs and had a similar body layout. Hadrosaurs were among the most dominant herbivores during the Late Cretaceous in Asia and North America, and during the close of the Cretaceous several lineages dispersed into Europe, Africa, South America and Antarctica. Like other ornithischians, hadrosaurids had a predentary bone and a pubic bone which was positioned backwards in the pelvis. Unlike more primitive iguanodonts, the teeth of hadrosaurids are stacked into complex structures known as dental batteries, which acted as effective g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hadrosauridae
Hadrosaurids (), or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which includes genera such as ''Edmontosaurus'' and ''Parasaurolophus'', was a common group of herbivores during the Late Cretaceous Period. Hadrosaurids are descendants of the Upper Jurassic/Lower Cretaceous iguanodontian dinosaurs and had a similar body layout. Hadrosaurs were among the most dominant herbivores during the Late Cretaceous in Asia and North America, and during the close of the Cretaceous several lineages dispersed into Europe, Africa, South America and Antarctica. Like other ornithischians, hadrosaurids had a predentary bone and a pubic bone which was positioned backwards in the pelvis. Unlike more primitive iguanodonts, the teeth of hadrosaurids are stacked into complex structures known as dental batteries, which acted as effective g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two Medicine Formation
The Two Medicine Formation is a geological formation, or rock body, in northwestern Montana and southern Alberta that was deposited between and (million years ago), during Campanian (Late Cretaceous) time. It crops out to the east of the Rocky Mountain Overthrust Belt, and the western portion (about thick) of this formation is folded and faulted while the eastern part, which thins out into the Sweetgrass Arch, is mostly undeformed plains. Below the formation are the nearshore (beach and tidal zone) deposits of the Virgelle Sandstone, and above it is the marine Bearpaw Shale. Throughout the Campanian, the Two Medicine Formation was deposited between the western shoreline of the Late Cretaceous Interior Seaway and the eastward advancing margin of the Cordilleran Overthrust Belt. The Two Medicine Formation is mostly sandstone, deposited by rivers and deltas. History of research In 1913 in paleontology, 1913, a US Geological Survey crew headed by Eugene Stebinger and a US Nationa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saurolophinae
Saurolophinae is a subfamily of hadrosaurid dinosaurs. It has since the mid-20th century generally been called the Hadrosaurinae, a group of largely non-crested hadrosaurs related to the crested sub-family Lambeosaurinae. However, the name Hadrosaurinae is based on the genus ''Hadrosaurus'' which was found in more recent studies to be more primitive than either lambeosaurines or other traditional "hadrosaurines", like ''Edmontosaurus'' and '' Saurolophus''. As a result of this, the name Hadrosaurinae was dropped or restricted to ''Hadrosaurus'' alone, and the subfamily comprising the traditional "hadrosaurines" was renamed the Saurolophinae. Recent phylogenetic work by Hai Xing indicates that ''Hadrosaurus'' is placed within the monophyletic group containing all non-lambeosaurine hadrosaurids. Under this view, the traditional Hadrosaurinae is resurrected, with the Hadrosauridae being divided into two clades: Hadrosaurinae and Lambeosaurinae. Saurolophinae was first defined as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hadrosaurus
''Hadrosaurus'' (; ) is a genus of hadrosaurid ornithopod dinosaurs that lived in North America during the Late Cretaceous Period in what is now the Woodbury Formation about 80 million to 78 million years ago. The holotype specimen was found in fluvial marine sedimentation, meaning that the corpse of the animal was transported by a river and washed out to sea. They were large animals ranging from and . Most of the preserved elements are very robust, unusual traits in hadrosaurs. ''Hadrosaurus'' were ponderously-built animals equipped with keratinous beaks for cropping foliage and a specialized and complex dentition for food processing. ''Hadrosaurus foulkii'', the only species in this genus, is known from a single specimen consisting of much of the skeleton and parts of the skull. The specimen was collected in 1858 from the Woodbury Formation in New Jersey, US, representing the first dinosaur species known from more than isolated teeth to be identified in North America. Using r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telmatosaurus
''Telmatosaurus'' (meaning "marsh lizard") is a genus of basal hadrosauromorph dinosaur from the Late Cretaceous of Romania. It was a relatively small hadrosaur, measuring approximately in length and in body mass, which has been explained as an instance of insular dwarfism. Discovery In 1895 some peasants presented Ilona Nopcsa, the daughter of their lord, with a dinosaur skull they had found at the estate Săcele in the district Hunedoara (then named Hunyad) in Transylvania. Ilona had an elder brother, Ferenc or Franz Nopcsa von Felső-Szilvás who was inspired by the find to become a paleontology student at the University of Vienna. In 1899 Nopcsa named the skull ''Limnosaurus transsylvanicus''. The generic name was derived from Greek λιμνή, ''limné'', "swamp", a reference to the presumed swamp-dwelling habits of hadrosaurs. The specific name referred to Transylvania. Later Nopcsa discovered that the name ''Limnosaurus'' had already been used by Othniel Charles Mars ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lophorhothon
''Lophorhothon'' is a genus of hadrosauroid dinosaur from the Late Cretaceous, the first genus of dinosaur discovered in Alabama, in the United States. Discovery and naming Remains of this small, poorly known perhaps saurolophine dinosaur were first discovered during the 1940s, from extensive erosional outcrops of the lower unnamed member of the Mooreville Chalk Formation (Selma Group; lower and middle Campanian) in Dallas County, Alabama, Dallas County, west of the town of Selma, Alabama. The taxon has since also been reported from Black Creek Formation (Campanian) of North Carolina. The holotype, which is housed in the collections of the Field Museum of Natural History, Field Museum in Chicago, consists of a fragmentary and disarticulated skull and incomplete postcranial skeleton. The length on the holotype specimen has been estimated as . The genus was named by Wann Langston in 1960. It was thought to be the only species of hadrosaur from that fossil formation, until 2016 w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
