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Deltadromeus Scale
''Deltadromeus'' (meaning "delta runner") is an extinct genus of controversial theropod dinosaurs from the Aoufous Formation (Kem Kem Beds) of Morocco. The genus contains a single species, ''Deltadromeus agilis'', known from multiple partial skeletons from the mid-Cretaceous period (mid-Cenomanian age), about 95 million years ago. The classification of ''Deltadromeus'' has been in flux since its original description. In 2016, the South American megaraptoran ''Gualicho'' was noted to have many similarities with ''Deltadromeus''. Other studies have considered it a ceratosaurian, potentially as a member of the family Noasauridae. It may be a junior synonym of the contemporary ''Bahariasaurus''. Discovery The holotype of ''Deltadromeus agilis'' (museum catalogue number SGM-Din2) is a partial skeleton. A number of specimens (catalogued under IPHG 1912 VIII) from the Bahariya Formation of Egypt were originally considered by Ernst Stromer to be conspecific with ''Bahariasaurus'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deltadromeus In Japan
''Deltadromeus'' (meaning "delta runner") is an extinct genus of controversial theropod dinosaurs from the Aoufous Formation (Kem Kem Beds) of Morocco. The genus contains a Monotypic taxon, single species, ''Deltadromeus agilis'', known from multiple partial skeletons from the mid-Cretaceous period (mid-Cenomanian age), about 95 million years ago. The classification of ''Deltadromeus'' has been in flux since its original description. In 2016, the South American megaraptoran ''Gualicho'' was noted to have many similarities with ''Deltadromeus''. Other studies have considered it a ceratosaurian, potentially as a member of the family Noasauridae. It may be a junior synonym of the contemporary ''Bahariasaurus''. Discovery The holotype of ''Deltadromeus agilis'' (museum catalogue number SGM-Din2) is a partial skeleton. A number of specimens (catalogued under IPHG 1912 VIII) from the Bahariya Formation of Egypt were originally considered by Ernst Stromer to be conspecific with ''Ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent 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, Aus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megaraptora
Megaraptora is a clade of carnivorous theropod dinosaurs. Its derived members, the Megaraptoridae are noted for their large hand claws and powerfully-built forelimbs, which are usually reduced in size in other large theropods. Although undoubtedly members of the clade Tetanurae, their relationships to others members of this group have been subject to dispute. Megaraptorans are incompletely known, and no complete megaraptoran skeleton has been found. However, they still possessed a number of unique features. Their forelimbs were large and strongly built, and the ulna bone had a unique shape in members of the family Megaraptoridae, a subset of megaraptorans which excludes '' Fukuiraptor'' and '' Phuwiangvenator''. The first two fingers were elongated, with massive curved claws, while the third finger was small. Megaraptoran skull material is very incomplete, but a juvenile ''Megaraptor'' described in 2014 preserved a portion of the snout, which was long and slender. Leg bones ref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aoniraptor
''Aoniraptor'' is an extinct genus of megaraptoran theropod dinosaurs from the Late Cretaceous Huincul Formation of Argentina. The genus contains a single species, ''Aoniraptor libertatem'', known from a partial skeleton. Discovery and naming The holotype, MPCA-Pv 804/1 to 804/25, which consists of the last sacral vertebra, six proximal caudal vertebrae, four mid-caudal vertebrae, and five haemal arches, was recovered by Matias Motta from the Violante Farm, part of the Huincul Formation. It was discovered in 2010, but only formally described in 2016. ''Aoniraptor'' comes from the Tehuelche language word "Aoni", which means south, and the Latin word "raptor", meaning thief. The specific name, ''libertatem'', comes from the Latin word for freedom, as it was discovered on the bicentennial of Argentina's independence from Spain in 1810. Description ''Aoniraptor'' grew up to long. On some blogs, ''Aoniraptor'' has been informally considered as synonymous with the theropod ''Guali ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sister Taxon
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and taxon B are sister groups to each other. Taxa A and B, together with any other extant or extinct descendants of their most recent common ancestor (MRCA), form a monophyletic group, the clade AB. Clade AB and taxon C are also sister groups. Taxa A, B, and C, together with all other descendants of their MRCA form the clade ABC. The whole clade ABC is itself a subtree of a larger tree which offers yet more sister group relationships, both among the leaves and among larger, more deeply rooted clades. The tree structure shown connects through its root to the rest of the universal tree of life. In cladistic standards, taxa A, B, and C may represent specimens, species, genera, or any other taxonomic units. If A and B are at the same taxonomic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neovenatoridae
Carnosauria is an extinct group of carnivorous theropod dinosaurs that lived during the Jurassic and Cretaceous periods. While Carnosauria was historically considered largely synonymous with Allosauroidea, some recent studies have revived Carnosauria as clade including both Allosauroidea and Megalosauroidea (which is sometimes recovered as paraphyletic with respect to Allosauroidea), and thus including the majority of non-coelurosaurian members of theropod clade Tetanurae. Other researchers have found Allosauroidea and Megalosauroidea to be unrelated groups.Cau A. (2024)A Unified Framework for Predatory Dinosaur Macroevolution Bollettino della Società Paleontologica Italiana, 63(1): 1-19. Distinctive characteristics of carnosaurs include large eye sockets, a long narrow skull and modifications of the legs and pelvis such as the thigh (femur) being longer than the shin (tibia). Carnosaurs first appeared in the Middle Jurassic around , and the last definitive carnosaur family ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ornitholestes
''Ornitholestes'' (meaning "bird robber") is a small theropod dinosaur of the late Jurassic ( Brushy Basin Member of the Morrison Formation, middle Kimmeridgian age, about 154 million years agoTurner, C.E. and Peterson, F., (1999). "Biostratigraphy of dinosaurs in the Upper Jurassic Morrison Formation of the Western Interior, U.S.A." Pp. 77–114 in Gillette, D.D. (ed.), ''Vertebrate Paleontology in Utah''. Utah Geological Survey Miscellaneous Publication 99-1.) of Western Laurasia (the area that was to become North America). To date, ''Ornitholestes'' is known only from a single partial skeleton with a badly crushed skull found at the Bone Cabin Quarry near Medicine Bow, Wyoming, in 1900. It was described by Henry Fairfield Osborn in 1903. An incomplete hand was later attributed to ''Ornitholestes'', although it now appears to belong to '' Tanycolagreus''. The type (and only known) species is ''O. hermanni''. The specific name honors the American Museum of Natural History prepa ... [...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] |
Coelurosaur
Coelurosauria (; from Greek, meaning "hollow-tailed lizards") is the clade containing all theropod dinosaurs more closely related to birds than to carnosaurs. Coelurosauria is a subgroup of theropod dinosaurs that includes compsognathids, tyrannosauroids, ornithomimosaurs, maniraptorans, and over the recent years, megaraptorans (Although position within the clade is unclear). Maniraptora includes birds, the only known dinosaur group alive today. In the past, Coelurosauria was used to refer to all small theropods, but this classification has since been amended. Most feathered dinosaurs discovered so far have been coelurosaurs. Philip J. Currie had considered it likely and probable that all coelurosaurs were feathered. However, several skin impressions found for some members of this group show pebbly, scaly skin, indicating that feathers did not completely replace scales in all taxa. Anatomy Bodyplan The studying of anatomical traits in coelurosaurs indicates that the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
