|
Dromaeosaurines
Dromaeosaurinae is a subfamily of the theropod group Dromaeosauridae. The earliest dromaeosaurine is ''Utahraptor'', dating back to the Early Cretaceous period in North America, however, some isolated teeth seems to represent an indeterminate species of dromaeosaurine, coming from the Late Jurassic period in Africa. If true, this will push their range to the Jurassic period, instead of the Cretaceous, as in most dromaeosaurs. Most dromaeosaurs are small carnivores, however, dromaeosaurines are represented by some of the largest species (''Achillobator'', ''Dakotaraptor'', ''Utahraptor''). So far, ''Dakotaraptor'' is the only dromaeosaurine with evidence of quill knobs, indicating a plumage; based on this, other members likely had them. Paleobiogeography Most dromaeosaurines lived in what is now Asia, North America and possibly Denmark during the Cretaceous period, from the Berriasian to the Maastrichtian stages. However, isolated teeth that may belong to African dromaeosaurine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dromaeosauridae
Dromaeosauridae () is a family of feathered theropod dinosaurs. They were generally small to medium-sized feathered carnivores that flourished in the Cretaceous Period. The name Dromaeosauridae means 'running lizards', from Greek ('), meaning 'runner', and ('), meaning 'lizard'. In informal usage, they are often called raptors (after ''Velociraptor''), a term popularized by the film '' Jurassic Park''; a few types include the term "raptor" directly in their name and have come to emphasize their bird-like appearance and speculated bird-like behavior. Dromaeosaurid fossils have been found across the globe in North America, Europe, Africa, Asia, South America and Antarctica, with some fossils giving credence to the possibility that they inhabited Australia as well. They first appeared in the mid-Jurassic Period (late Bathonian stage, about 167 million years ago) and survived until the end of the Cretaceous (Maastrichtian stage, 66 ma), existing until the Cretaceous–Paleogene ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Velociraptorinae
Velociraptorinae is a subfamily of the theropod group Dromaeosauridae. The earliest velociraptorines are probably ''Nuthetes'' from the United Kingdom, and possibly ''Deinonychus'' from North America. However, several indeterminate velociraptorines have also been discovered, dating to the Kimmeridgian stage, in the Late Jurassic Period. These fossils were discovered in the Langenberg quarry, Oker near Goslar, Germany.van der Lubbe, T., Richter, U. and Knotschke, N. (2009).Velociraptorine dromaeosaurid teeth from the Kimmeridgian (Late Jurassic) of Germany" ''Acta Palaeontologica Polonica'', 54(3): 401-408. Description While most velociraptorines were generally small animals, at least one species may have achieved gigantic sizes comparable to those found among the dromaeosaurines. So far, this unnamed giant velociraptorine is known only from isolated teeth found on the Isle of Wight, England. The teeth belong to an animal the size of dromaeosaurines of the genus ''Utahraptor'', bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deinonychus
''Deinonychus'' ( ; ) is a genus of dromaeosaurid theropod dinosaur with one described species, ''Deinonychus antirrhopus''. This species, which could grow up to long, lived during the early Cretaceous Period, about 115–108 million years ago (from the mid-Aptian to early Albian stages). Fossils have been recovered from the U.S. states of Montana, Utah, Wyoming, and Oklahoma, in rocks of the Cloverly Formation, Cedar Mountain Formation and Antlers Formation, though teeth that may belong to ''Deinonychus'' have been found much farther east in Maryland. Paleontologist John Ostrom's study of ''Deinonychus'' in the late 1960s revolutionized the way scientists thought about dinosaurs, leading to the " dinosaur renaissance" and igniting the debate on whether dinosaurs were warm-blooded or cold-blooded. Before this, the popular conception of dinosaurs had been one of plodding, reptilian giants. Ostrom noted the small body, sleek, horizontal posture, ratite-like spine, and esp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yurgovuchia
''Yurgovuchia'' (meaning "coyote") is a genus of dromaeosaurid theropod dinosaurs that lived in North America during the Early Cretaceous period in what is now the Cedar Mountain Formation. It contains a single species, ''Yurgovuchia doellingi''. The remains were discovered in Utah, United States. Discovery and naming The holotype was collected by Donald D. DeBlieux in 2005, from Don's Place, part of the Doelling's Bowl bone bed in Grand County, Utah. This bone bed is in the lower Yellow Cat Member of the Cedar Mountain Formation, dating probably to the Valanginian stage of the Early Cretaceous period, about 139–134.6 million years ago. ''Yurgovuchia'' was first described and named by Phil Senter, James I. Kirkland, Donald D. DeBlieux, Scott Madsen and Natalie Toth in 2012 and the type species is ''Yurgovuchia doellingi''. The generic name is derived from the Ute word ''yurgovuch'', meaning coyote, a predator of similar size to ''Y. doellingi'' which currentl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Velociraptor
''Velociraptor'' (; ) is a genus of small dromaeosaurid dinosaur that lived in Asia during the Late Cretaceous epoch, about 75 million to 71 million years ago. Two species are currently recognized, although others have been assigned in the past. The type species is ''V. mongoliensis''; fossils of this species have been discovered in the Djadochta Formation, Mongolia. A second species, ''V. osmolskae'', was named in 2008 for skull material from the Bayan Mandahu Formation, China. Smaller than other dromaeosaurids like ''Deinonychus'' and ''Achillobator'', ''Velociraptor'' was about long with a body mass between . It nevertheless shared many of the same anatomical features. It was a bipedal, feathered carnivore with a long tail and an enlarged sickle-shaped claw on each hindfoot, which is thought to have been used to tackle and restrain prey. ''Velociraptor'' can be distinguished from other dromaeosaurids by its long and low skull, with an upturned snout. ''Velociraptor'' (com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dromaeosaurus Albertensis
''Dromaeosaurus'' (, "running lizard") is a genus of dromaeosaurid theropod dinosaur which lived during the Late Cretaceous period (middle late Campanian and Maastrichtian), sometime between 80 and 69 million years ago, in Alberta, Canada and the western United States. The type species is ''Dromaeosaurus albertensis'', which was described by William Diller Matthew and Barnum Brown in 1922. Its fossils were unearthed in the Dinosaur Park Formation. Teeth attributed to this genus have been found in the Prince Creek Formation. ''Dromaeosaurus'' is the type genus of both Dromaeosauridae and Dromaeosaurinae, which include many genera with similar characteristics to ''Dromaeosaurus'' such as possibly its closest relative ''Dakotaraptor''. ''Dromaeosaurus'' was heavily built, more so than other dromaeosaurs that are similar in size, like ''Velociraptor''. Discovery and naming Despite receiving widespread attention in popular books on dinosaurs, and the usage of a complete mounted skelet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area and 20% of its land area.Sayre, April Pulley (1999), ''Africa'', Twenty-First Century Books. . With billion people as of , it accounts for about of the world's human population. Africa's population is the youngest amongst all the continents; the median age in 2012 was 19.7, when the worldwide median age was 30.4. Despite a wide range of natural resources, Africa is the least wealthy continent per capita and second-least wealthy by total wealth, behind Oceania. Scholars have attributed this to different factors including geography, climate, tribalism, colonialism, the Cold War, neocolonialism, lack of democracy, and corruption. Despite this low concentration of wealth, recent economic expansion and the large and young population make Afr ... [...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] |
Tyrannosauridae
Tyrannosauridae (or tyrannosaurids, meaning "tyrant lizards") is a family of coelurosaurian theropod dinosaurs that comprises two subfamilies containing up to thirteen genera, including the eponymous ''Tyrannosaurus''. The exact number of genera is controversial, with some experts recognizing as few as three. All of these animals lived near the end of the Cretaceous Period and their fossils have been found only in North America and Asia. Although descended from smaller ancestors, tyrannosaurids were almost always the largest predators in their respective ecosystems, putting them at the apex of the food chain. The largest species was ''Tyrannosaurus rex'', one of the largest and most massive known land predators, which measured over in length and according to most modern estimates to in weight. Tyrannosaurids were bipedal carnivores with massive skulls filled with large teeth. Despite their large size, their legs were long and proportioned for fast movement. In contrast, their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barnum Brown
Barnum Brown (February 12, 1873 – February 5, 1963), commonly referred to as Mr. Bones, was an American paleontologist. Named after the circus showman P. T. Barnum, he discovered the first documented remains of ''Tyrannosaurus'' during a career that made him one of the most famous fossil hunters working from the late Victorian era into the early 20th century. Fossil dinosaur expeditions Sponsored by the American Museum of Natural History (AMNH), Brown traversed the country bargaining and trading for fossils. His field was not limited to dinosaurs. He was known to collect or obtain anything of possible scientific value. Often, he simply sent money to have fossils shipped to the AMNH, and any new specimen of interest often resulted in a flurry of letters between the discoverer and Brown. After working a handful of years in Wyoming for AMNH in the late 1890s, Brown led an expedition to the Hell Creek Formation of southeastern Montana. There, in 1902, he discovered and exca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Diller Matthew
William Diller Matthew Royal Society, FRS (February 19, 1871 – September 24, 1930) was a vertebrate paleontologist who worked primarily on mammal fossils, although he also published a few early papers on mineralogy, petrological geology, one on botany, one on trilobites, and he described ''Tetraceratops insignis'', which was much later suggested to be the oldest known (Cisuralian, Early Permian) therapsid. Matthew was born in Saint John, New Brunswick, Saint John, New Brunswick, the son of George Frederic Matthew and Katherine (Diller) Matthew. His father was an amateur geologist and paleontologist who instilled his son with an abiding interest in the earth sciences. Matthew received an A.B. at the University of New Brunswick in 1889 and then earned his Ph.D. at Columbia University in 1894. Matthew was curator of the American Museum of Natural History from the mid-1890s to 1927, and director of the University of California Museum of Paleontology from 1927 to 1930. He was the fat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denticle (tooth Feature)
Denticles, also called serrations, are small bumps on a tooth that serve to give the tooth a serrated edge. In paleontology, denticle characteristics such as size and density (denticles per unit distance) are used to describe and classify fossilized teeth, especially those of dinosaurs. Denticles are also present on the teeth of varanoid lizards, sharks, and mammals. The term is also used to describe the analogous radular teeth of mollusks. Archived aPDF File:Dromaeosauridae tooth.TIF, Dromaeosauridae tooth with small denticles along the cutting edge. Scale bars are 1 mm. File:Ankylosaurus tooth.jpg, ''Ankylosaurus'' tooth with large denticles. File:Dentary teeth of Segnosaurus.png, ''Segnosaurus ''Segnosaurus'' is a genus of therizinosaurid dinosaur that lived in what is now southeastern Mongolia during the Late Cretaceous, about 102–86 million years ago. Multiple incomplete but well-preserved specimens were discovered in the Go ...'' dentition featuring a tripl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.svg "Click for more on -> Africa")
