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Bagaceratopidae
Protoceratopsidae is a family of basal (primitive) ceratopsians from the Late Cretaceous period. Although ceratopsians have been found all over the world, protoceratopsids are only definitively known from Cretaceous strata in Asia, with most specimens found in China and Mongolia. As ceratopsians, protoceratopsids were herbivorous, with constantly replacing tooth batteries made for slicing through plants and a hooked beak for grabbing them. Protoceratopsids were small ceratopsians around 1-2.5 m in length. Their bony frill and horns were much smaller than more derived members of Ceratopsia, such as ceratopsids. Description Protoceratopsids were relatively small ceratopsians, averaging around 1-2.5 m in length from head to tail. Protoceratopsids have a frill and rostral bone characteristic of all ceratopsians. Their snout is particularly wedge-shaped with tall and narrow nostrils situated high on it. The antorbital fenestra is unusually small, and the antorbital fossa sits high o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protoceratopsidae Size Comparison
Protoceratopsidae is a family of basal (primitive) ceratopsians from the Late Cretaceous period. Although ceratopsians have been found all over the world, protoceratopsids are only definitively known from Cretaceous strata in Asia, with most specimens found in China and Mongolia. As ceratopsians, protoceratopsids were herbivorous, with constantly replacing tooth batteries made for slicing through plants and a hooked beak for grabbing them. Protoceratopsids were small ceratopsians around 1-2.5 m in length. Their bony frill and horns were much smaller than more derived members of Ceratopsia, such as ceratopsids. Description Protoceratopsids were relatively small ceratopsians, averaging around 1-2.5 m in length from head to tail. Protoceratopsids have a frill and rostral bone characteristic of all ceratopsians. Their snout is particularly wedge-shaped with tall and narrow nostrils situated high on it. The antorbital fenestra is unusually small, and the antorbital fossa sits high on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bagaceratops
''Bagaceratops'' (meaning "small-horned face") is a genus of small protoceratopsid dinosaurs that lived in Asia during the Late Cretaceous, around 72 to 71 million years ago. ''Bagaceratops'' remains have been reported from the Barun Goyot Formation and Bayan Mandahu Formation. One specimen may argue the possible presence of ''Bagaceratops'' in the Djadochta Formation. ''Bagaceratops'' was among the smallest ceratopsians, growing up to in length, with a weight about . Although emerging late in the reign of the dinosaurs, ''Bagaceratops'' had a fairly primitive anatomy—when compared to the much derived ceratopsids—and kept the small body size that characterized early ceratopsians. Unlike its close relative, ''Protoceratops'', ''Bagaceratops'' lacked premaxillary teeth (cylindrical, blunt teeth near the tip of the upper jaw). History of discovery During the large field work of the Polish-Mongolian Palaeontological Expeditions in the 1970s, abundant protoceratopsid specimens ... [...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] |
Graciliceratops
''Graciliceratops'' (meaning "slender horn") is a genus of Ceratopsia#Phylogeny, neoceratopsian dinosaurs that lived in Asia during the Late Cretaceous period. Discovery and naming The holotype, ZPAL MgD-I/156, was discovered at the Bayan Shireh Formation in Mongolia, coming from the Sheeregeen Gashoon locality near Sainshand. The discoveries were made during field exploration by the Polish-Mongolian Palaeontological Expedition, in 1971. Four years later, in 1975, the specimen was described by Teresa Maryańska and Halszka Osmólska and referred to the genus ''Microceratops''. However, Paul Sereno noted that the referral for this specimen was injustified and overall, the genus lacked diagnosis, therefore, ''Microceratops'' (now named ''Microceratus'') was considered a nomen dubium. The referred specimen was redescribed by him, creating a new genus and species: ''Graciliceratops mongoliensis''. The holotype is fragmentary, consisting of a very fragmented skull with mandibles; ver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leptoceratopsidae
Leptoceratopsidae is an extinct family of neoceratopsian dinosaurs from Asia, North America and Europe. Leptoceratopsids resembled, and were closely related to, other neoceratopsians, such as the families Protoceratopsidae and Ceratopsidae, but they were more primitive and generally smaller. Phylogeny Leptoceratopsidae was originally named by Franz Nopcsa von Felső-Szilvás in 1923 as a subfamily Leptoceratopsinae, and its type species is ''Leptoceratops gracilis''. Mackovicky, in 2001, defined it as a stem-based taxon and a family consisting of ''Leptoceratops gracilis'' and all species closer to ''Leptoceratops'' than to ''Triceratops horridus''.Makovicky, P.J. 2001. A ''Montanoceratops cerorhynchus'' (Dinosauria: Ceratopsia) braincase from the Horseshoe Canyon Formation of Alberta, In: Tanke, D.H. & Carpenter, K. (Eds.). ''Mesozoic Vertebrate Life''. Bloomington: Indiana University Press. Pp. 243-262. The cladogram below follows the topologies from a 2015 analysis by Yiming ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Montanoceratops
''Montanoceratops'' is an extinct genus of small ceratopsian dinosaur that lived approximately 70 million years ago during the latter part of the Cretaceous Period in what is now Montana and Alberta. ''Montanoceratops'' was a small sized, moderately-built, ground-dwelling, quadrupedal herbivore, that could grow up to an estimated in length and in body mass. Description ''Montanoceratops'' was a typical primitive ceratopsian in many respects, distinguished from the later species by the presence of claws, rather than hooves, and by having teeth in its upper jaw, rather than a toothless beak. It was once thought to have a horn on its nose but that was a misplaced cheek horn.Holtz, Thomas R. Jr. (2008) ''Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages'Supplementary Information/ref> According to Brown and Schlaikjer (1935), ''Montanoceratops'' can be distinguished based on the following characteristics: * the nasal bone is proportionally lar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leptoceratops
''Leptoceratops'' (meaning 'Thin-horned face' and derived from Greek ''lepto-/λεπτο-'' meaning 'small', 'insignificant', 'slender', 'meagre' or 'lean', ''kerat-/κερατ-'' meaning 'horn' and ''-ops/ωψ'' meaning face), is a genus of leptoceratopsid ceratopsian dinosaurs from the late Cretaceous Period (late Maastrichtian age, 68.8-66 Ma ago) of what is now Western North America. Their skulls have been found in Alberta, Canada and Wyoming. Description ''Leptoceratops'' could probably stand and run on their hind legs: analysis of forelimb function indicates that even though they could not pronate their hands, they could walk on four legs. Paul proposed that ''Leptoceratops'' was around long and could have weighed , but Tereschenko proposed a maximum length of . Discovery and species The first small ceratopsian named ''Leptoceratops'' was discovered in 1910 by Barnum Brown in the Red Deer Valley in Alberta, Canada. He described it four years later. The first specimen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monophyletic
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic groups are typically characterised by shared derived characteristics ( synapomorphies), which distinguish organisms in the clade from other organisms. An equivalent term is holophyly. The word "mono-phyly" means "one-tribe" in Greek. Monophyly is contrasted with paraphyly and polyphyly as shown in the second diagram. A ''paraphyletic group'' consists of all of the descendants of a common ancestor minus one or more monophyletic groups. A '' polyphyletic group'' is characterized by convergent features or habits of scientific interest (for example, night-active primates, fruit trees, aquatic insects). The features by which a polyphyletic group is differentiated from others are not inherited from a common ancestor. These definitions have tak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triceratops
''Triceratops'' ( ; ) is a genus of herbivore, herbivorous Chasmosaurinae, chasmosaurine Ceratopsidae, ceratopsid dinosaur that first appeared during the late Maastrichtian stage of the Late Cretaceous Period (geology), 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, Cretaceous–Paleogene extinction event 66 million years ago. The name ''Triceratops'', which literally means 'three-horned face', is derived from the Ancient Greek, Greek words () meaning 'three', () meaning 'horn', and () meaning 'face'. Bearing a large bony neck frill, frill, three horn (anatomy), 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 m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, the equivalent Latin term ''cladus'' (plural ''cladi'') is often used in taxonomical literature. The common ancestor may be an individual, a population, or a species (extinct or extant). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed monophyletic (Greek: "one clan") groups. Over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming taxa that are not clades; that is, taxa that are not monophyletic. Some of the relationships between organisms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul Sereno
Paul Callistus Sereno (born October 11, 1957) is a professor of paleontology at the University of Chicago and a National Geographic "explorer-in-residence" who has discovered several new dinosaur species on several continents, including at sites in Inner Mongolia, Argentina, Morocco and Niger. One of his most widely publicized discoveries is that of a nearly complete specimen of ''Sarcosuchus imperator'' — popularly known as SuperCroc — at Gadoufaoua in the Tenere desert of Niger. Biography Youth and education The son of a mail carrier and an art teacher at Prairie Elementary, Sereno grew up in Naperville, Illinois and graduated from Naperville Central High School. He was then educated at Northern Illinois University (B.S., Biological Sciences, 1979) and Columbia University (M.A., Vertebrate Paleontology, 1981; M. Phil., Geological Sciences, 1981; Ph.D., Geological Sciences, 1987). Career Sereno was named one of ''People'' magazine's 50 Most Beautiful People (1997). Ser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William King Gregory
William King Gregory (May 19, 1876 – December 29, 1970) was an American zoologist, renowned as a primatologist, paleontologist, and functional and comparative anatomist. He was an expert on mammalian dentition, and a leading contributor to theories of evolution. In addition he was active in presenting his ideas to students and the general public through books and museum exhibits. Early life He was born in Greenwich Village, New York, on May 19, 1876 to George Gregory and Jane King Gregory. He attended Trinity School and then moved onto Columbia University in 1895, initially at the School of Mines but then transferring to Columbia College. He majored in zoology and vertebrate paleontology under Henry Fairfield Osborn. While still an undergraduate he became Osborn's research assistant and soon after married Laura Grace Foote. He received his undergraduate degree from Columbia in 1900, followed by a masters in 1905, and a doctorate in 1910. Academic career He developed an earl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
