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Dilophosaurus Wetherilli
''Dilophosaurus'' ( ) is a genus of theropod dinosaurs that lived in what is now North America during the Early Jurassic, about 193 million years ago. Three skeletons were discovered in northern Arizona in 1940, and the two best preserved were collected in 1942. The most complete specimen became the holotype of a new species in the genus '' Megalosaurus'', named ''M. wetherilli'' by Samuel P. Welles in 1954. Welles found a larger skeleton belonging to the same species in 1964. Realizing it bore crests on its skull, he assigned the species to the new genus ''Dilophosaurus'' in 1970, as ''Dilophosaurus wetherilli''. The genus name means "two-crested lizard", and the species name honors John Wetherill, a Navajo councilor. Further specimens have since been found, including an infant. Footprints have also been attributed to the animal, including resting traces. Another species, ''Dilophosaurus sinensis'' from China, was named in 1993, but was later found to belong to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Jurassic
The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic-Jurassic extinction event, 201.3 Ma (million years ago), and ends at the start of the Middle Jurassic 174.1 Ma. Certain rocks of marine origin of this age in Europe are called "Lias Group, Lias" and that name was used for the period, as well, in 19th-century geology. In southern Germany rocks of this age are called Black Jurassic. Origin of the name Lias There are two possible origins for the name Lias: the first reason is it was taken by a geologist from an England, English quarryman's dialect pronunciation of the word "layers"; secondly, sloops from north Cornwall, Cornish ports such as Bude would sail across the Bristol Channel to the Vale of Glamorgan to load up with rock from coastal limestone quarries (lias limestone from S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keratin
Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, horns, claws, hooves, and the outer layer of skin among vertebrates. Keratin also protects epithelial cells from damage or stress. Keratin is extremely insoluble in water and organic solvents. Keratin monomers assemble into bundles to form intermediate filaments, which are tough and form strong unmineralized epidermal appendages found in reptiles, birds, amphibians, and mammals. Excessive keratinization participate in fortification of certain tissues such as in horns of cattle and rhinos, and armadillos' osteoderm. The only other biological matter known to approximate the toughness of keratinized tissue is chitin. Keratin comes in two types, the primitive, softer forms found in all vertebrates and harder, derived forms found only amon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sarahsaurus
''Sarahsaurus'' is a genus of basal sauropodomorph dinosaur which lived during the Early Jurassic period in what is now northeastern Arizona, United States. Discovery and naming All specimens of ''Sarahsaurus'' were collected from the Lower Jurassic Kayenta Formation near Gold Spring, Arizona. The genus is based on a nearly complete and articulated (with bones still connected to each other) skeleton with a fragmentary and disarticulated skull (holotype, specimen number TMM 43646-2). In addition, a partial skeleton (specimen number TMM 43646-3) as well as a nearly complete skull (specimen number MCZ 8893) was assigned to the genus. The latter specimen was originally referred to as ''Massospondylus'' sp. The complete skull is crushed and split horizontally, separating the skull roof from the palate; this split was caused by periodic swelling and shrinkage of the surrounding clay after burial. While the holotype individual was mature, the second skull indicates a less mature indi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scutellosaurus
''Scutellosaurus'' ( ) is a genus of thyreophoran ornithischian dinosaur that lived approximately 196 million years ago during the early part of the Jurassic Period in what is now Arizona, USA. It is classified in Thyreophora, the armoured dinosaurs; its closest relatives may have been ''Emausaurus'' and ''Scelidosaurus'', another armored dinosaur which was mainly a quadrupedal dinosaur, unlike bipedal ''Scutellosaurus''. It is one of the earliest representatives of the armored dinosaurs and the basalmost form discovered to date. ''Scutellosaurus'' was a small, lightly-built, ground-dwelling, herbivore, that could grow up to an estimated long. Etymology The genus name ''Scutellosaurus'' means "little-shielded lizard", and is derived from the Latin word "scutellum" meaning "little shield", and the Greek word "sauros" (σαύρα) meaning "lizard". The type and only valid species known today is ''Scutellosaurus lawleri''. The specific name honors David Lawler who collected the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kayenta Formation
The Kayenta Formation is a geological formation in the Glen Canyon Group that is spread across the Colorado Plateau province of the United States, including northern Arizona, northwest Colorado, Nevada, and Utah. Traditionally has been suggested as Sinemurian-Pliensbachian, but more recent dating of detrital zircons has yielded a depositional age of 183.7 ± 2.7 Ma, thus a Pliensbachian-Toarcian age is more likely A previous depth work recovered a solid Lower-Middle Pliensbachian age from measurements done in the Tenney Canyon. This rock formation is particularly prominent in southeastern Utah, where it is seen in the main attractions of a number of national parks and monuments. These include Zion National Park, Capitol Reef National Park, the San Rafael Swell, and Canyonlands National Park. The Kayenta Formation frequently appears as a thinner dark broken layer below Navajo Sandstone and above Wingate Sandstone (all three formations are in the same group). Together, these thre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleopathologies
Paleopathology, also spelled palaeopathology, is the study of ancient diseases and injuries in organisms through the examination of fossils, Mummy, mummified tissue, skeletal remains, and analysis of coprolites. Specific sources in the study of ancient human diseases may include early documents, illustrations from early books, painting and sculpture from the past. Looking at the individual roots of the word "Paleopathology" can give a basic definition of what it encompasses. "Paleo-" refers to "ancient, early, prehistoric, primitive, fossil." The suffix "-pathology" comes from the Latin ''pathologia'' meaning "study of disease." Through the analysis of the aforementioned things, information on the evolution of diseases as well as how past civilizations treated conditions are both valuable byproducts. Studies have historically focused on humans, but there is no evidence that humans are more prone to pathologies than any other animal. Paleopathology is an interdisciplinary science, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Selection
Sexual selection is a mode of natural selection in which members of one biological sex mate choice, choose mates of the other sex to mating, mate with (intersexual selection), and compete with members of the same sex for access to members of the opposite sex (intrasexual selection). These two forms of selection mean that some individuals have greater reproductive success than others within a population, for example because they are more Animal sexual behaviour, attractive or prefer more attractive partners to produce offspring. Successful males benefit from frequent mating and monopolizing access to one or more fertile females. Females can maximise the return on the energy they invest in reproduction by selecting and mating with the best males. The concept was first articulated by Charles Darwin who wrote of a "second agency" other than natural selection, in which competition between mate candidates could lead to speciation. The theory was given a mathematical basis by Ronald F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species Recognition
Intra-species recognition is the recognition by a member of a species of a conspecific (another member of the same species). In many species, such recognition is necessary for procreation. Different species may employ different methods, but all of them are based on one or more senses (after all, this is how the organism gathers information about the environment). The recognition may happen by chemical signature ( smell), by having a distinctive shape or color (sight), by emitting certain sounds (hearing), or even by behaviour patterns. Often a combination of these is used. Among human beings, the sense of sight is usually in charge of recognizing other members of the same species, with maybe the subconscious help of smell. In particular, the human brain has a disproportionate amount of processing power dedicated to finely analyze the features of a human face. This is why we are able to distinguish almost all human beings from each other (barring look-alikes), and a human being ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Display
Display behaviour is a set of ritualized behaviours that enable an animal to communicate to other animals (typically of the same species) about specific stimuli. These ritualized behaviours can be visual however many animals depend on a mixture of visual, audio, tactical and/or chemical signals as well. Evolution has tailored these stereotyped behaviours to allow animals to communicate both conspecifically and interspecifically which allows for a broader connection in different niches in an ecosystem. It is connected to sexual selection and survival of the species in various ways. Typically, display behaviour is used for courtship between two animals and to signal to the female that a viable male is ready to mate. In other instances, species may exhibit territorial display behaviour, in order to preserve a foraging or hunting territory for its family or group. A third form is exhibited by tournament species in which males will fight in order to gain the 'right' to breed. Animals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coelophysidae
Coelophysidae is a family of primitive carnivorous theropod dinosaurs. Most species were relatively small in size. The family flourished in the Late Triassic and Early Jurassic periods, and has been found on numerous continents. Many members of Coelophysidae are characterized by long, slender skulls and light skeletons built for speed. One member genus, ''Coelophysis'', displays the earliest known furcula in a dinosaur. Under Cladistics, cladistic analysis, Coelophysidae was first defined by Paul Sereno in 1998 as the most recent common ancestor of ''Coelophysis, Coelophysis bauri'' and ''Procompsognathus, Procompsognathus triassicus'', and all of that common ancestor's descendants. However, Tykoski (2005) has advocated for the definition to change to include the additional taxa of Coelophysis kayentakatae, "Syntarsus" ''kayentakatae'' and ''Segisaurus halli''. Coelophysidae is part of the superfamily Coelophysoidea, which in turn is a subset of the larger Neotheropoda clade. As p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dracovenator
''Dracovenator'' () is a genus of neotheropod dinosaur that lived approximately 201 to 199 million years ago during the early part of the Jurassic Period in what is now South Africa. ''Dracovenator'' was a medium-sized, moderately-built, ground-dwelling, bipedal carnivore, that could grow up to an estimated in length and in body mass. Its type specimen was based on only a partial skull that was recovered. Discovery The type material BP/1/5243 for ''Dracovenator'' was discovered at the "Upper Drumbo Farm" locality in the upper Elliot Formation which is part of the Stormberg Group in Eastern Cape Province, South Africa. It was collected by James Kitching and Regent "Lucas" Huma in sandstone that was deposited during the Hettangian stage of the Jurassic period, approximately 201 to 199 million years ago. The paratype material BP/1/5278 (originally assigned to ''Syntarsus rhodesiensis'') was discovered in 1981, also at the Elliot Formation in pinkish-maroon silty mudstone that w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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