HOME





Robert J. Gay
Robert Joseph Gay is an American Paleontologist known for his work in the Chinle and Kayenta Formations in the southwest United States. He is known for his studies of cannibalism in ''Coelophysis'' and sexual dimorphism in ''Dilophosaurus,'' and his fieldwork in Bears Ears National Monument. In 2017, he and coauthors formally published their study on the oldest known dinosaur from Utah, a neotheropod that is likely an animal similar to ''Coelophysis''. Robert Gay is currently the Curator of Education at the Idaho Museum of Natural History Discoveries In the summer of 2015, Gay discovered the first occurrence of ''Crosbysaurus'' from the Triassic of Utah.Gay, R. J., & Aude, I. S. (2015). The first occurrence of the enigmatic archosauriform Crosbysaurus Heckert 2004 from the Chinle Formation of southern Utah. PeerJ, 3. doi:10.7717/peerj.905 In 2017, Robert Gay and others published their discovery on the oldest known dinosaur from Utah, a small ''Coelophysis ''Coelophysis'' ( ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

University Of Arizona
The University of Arizona (Arizona, U of A, UArizona, or UA) is a Public university, public Land-grant university, land-grant research university in Tucson, Arizona, United States. Founded in 1885 by the 13th Arizona Territorial Legislature, it was the first university established in the Arizona Territory. The University of Arizona is one of three universities governed by the Arizona Board of Regents (the University of Arizona, Arizona State University, and Northern Arizona University). , the university enrolled 53,187 students in 22 separate colleges/schools, including the Eller College of Management, the Wyant College of Optical Sciences, the University of Arizona College of Medicine – Phoenix, College of Medicine – Phoenix, the University of Arizona College of Medicine – Tucson, College of Medicine – Tucson, and the James E. Rogers College of Law. The university is Carnegie Classification of Institutions of Higher Education, classified among "R1: Doctoral Universities ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Chinle Formation
The Chinle Formation is an Upper Triassic continental geological formation of fluvial, lacustrine, and palustrine to eolian deposits spread across the U.S. states of Nevada, Utah, northern Arizona, western New Mexico, and western Colorado. In New Mexico, it is often raised to the status of a geological group, the Chinle Group. Some authors have controversially considered the Chinle to be synonymous to the Dockum Group of eastern Colorado and New Mexico, western Texas, the Oklahoma panhandle, and southwestern Kansas. The Chinle Formation is part of the Colorado Plateau, Basin and Range, and the southern section of the Interior Plains.GEOLEX database entry for Chinle
USGS (viewed 19 March 2006)
A probable separate depositional basin within the Chinle is found in northwestern Colorado and northeaste ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Kayenta Formation
The Kayenta Formation is a geological formation in the Glen Canyon Group that is spread across the Colorado Plateau area of the United States, including northern Arizona, northwest Colorado, Nevada, and Utah. Originally suggested as being Sinemurian-Pliensbachian, but more recent Detrital zircon geochronology, 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 "Carixian" (Lower-Middle Pliensbachian) age from measurements done in the Tenney Canyon. More recent works have provided varied datations for the layers, with samples from Colorado and Arizona suggesting 197.0±1.5-195.2±5.5 Ma (Middle Sinemurian), while the topmost section is likely Toarcian or close in age, maybe even recovering terrestrial deposits coeval with the Toarcian Oceanic Anoxic Event. This last age assignation also correlated the Toarcian Vulcanism on the west Cordilleran Magmatic Arc, as the num ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 contiguous states border Canada to the north and Mexico to the south, with the semi-exclave of Alaska in the northwest and the archipelago of Hawaii in the Pacific Ocean. The United States asserts sovereignty over five Territories of the United States, major island territories and United States Minor Outlying Islands, various uninhabited islands in Oceania and the Caribbean. It is a megadiverse country, with the world's List of countries and dependencies by area, third-largest land area and List of countries and dependencies by population, third-largest population, exceeding 340 million. Its three Metropolitan statistical areas by population, largest metropolitan areas are New York metropolitan area, New York, Greater Los Angeles, Los Angel ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Coelophysis
''Coelophysis'' ( Traditional English pronunciation of Latin, traditionally; or , as heard more commonly in recent decades) is a genus of coelophysid Theropoda, theropod dinosaur that lived Approximation, approximately 215 to 201.4 million years ago during the Late Triassic Period (geology), period from the middle Norian to Rhaetian age in what is now the southwestern United States. ''Megapnosaurus'' was once considered to be a species within this genus, but this interpretation has been challenged and the genus ''Megapnosaurus'' is now considered valid. ''Coelophysis'' was a small, slenderly built, ground-dwelling, bipedal carnivore that could grow up to long. It is one of the earliest known dinosaur genera. Scattered material representing similar animals has been found worldwide in some Late Triassic and Early Jurassic formations. The type species ''C. bauri'', originally given to the genus ''Coelurus'' by Edward Drinker Cope in 1887, was described by the latter in 1889. T ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Sexual Dimorphism
Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, dioecious species, which consist of most animals and some plants. Differences may include secondary sex characteristics, size, weight, color, markings, or behavioral or cognitive traits. Male-male reproductive competition has evolved a diverse array of sexually dimorphic traits. Aggressive utility traits such as "battle" teeth and blunt heads reinforced as battering rams are used as weapons in aggressive interactions between rivals. Passive displays such as ornamental feathering or song-calling have also evolved mainly through sexual selection. These differences may be subtle or exaggerated and may be subjected to sexual selection and natural selection. The opposite of dimorphism is ''monomorphism'', when both biological sexes are phenotype, ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Dilophosaurus
''Dilophosaurus'' ( ) is a genus of theropod dinosaurs that lived in what is now North America during the Early Jurassic, about 186 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. Fossil 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 belon ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Neotheropod
Theropoda (; from ancient Greek , (''therion'') "wild beast"; , (''pous, podos'') "foot"">wiktionary:ποδός"> (''pous, podos'') "foot" is one of the three major groups (clades) of dinosaurs, alongside Ornithischia and Sauropodomorpha. Theropods, both extant and extinct, are characterized by hollow bones and three toes and claws on each limb. They are generally classed as a group of saurischian dinosaurs, placing them closer to sauropodomorphs than to ornithischians. They were ancestrally carnivorous, although a number of theropod groups evolved to become herbivores and omnivores. Members of the subgroup Coelurosauria and possibly some other or all theropods were covered in feathers. In the Jurassic, birds evolved from small specialized coelurosaurian theropods, and are currently represented by about 11,000 living species, making theropods the only group of dinosaurs alive today. Theropods first appeared during the Carnian age of the late Triassic period 231.4& ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Crosbysaurus
''Crosbysaurus'' is a genus of extinct archosauromorph that lived in the Late Triassic of Arizona, New Mexico, North Carolina, Texas, and Utah. It is known from the Chinle Formation and Dockum Group rock units from the southwestern United States. The type species is ''C. harrisae'', and the only known material includes teeth. 11 specimens are known, each including a single tooth. ''Crosbysaurus'' was originally identified as an ornithischian dinosaur by Andrew Heckert when it was first described in 2004. Further work has shown that it is likely an archosauromorph based on the features of its teeth, and it may belong to Archosauriformes Archosauriformes (Ancient Greek, Greek for 'ruling lizards', and Latin for 'form') is a clade of diapsid reptiles encompassing Archosaur, archosaurs and some of their close relatives. It was defined by Jacques Gauthier (1994) as the clade stemmin .... The taxon is likely valid as it differs from other genera from the same region known from t ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Triassic
The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is the first and shortest period of the Mesozoic Era and the seventh period of the Phanerozoic Eon. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic. The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it was well into the middle of the Triassic before life recovered its former diversity. Three categories of organisms can be distinguished in the Triassic record: survivors from the extinction event, new groups that flourished briefly, and other new groups that went on to dominate the Mesozoic Era. Reptiles, especially archosaurs, were the ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Utah
Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northeast, Idaho to the north, and Nevada to the west. In comparison to all the U.S. states and territories, Utah, with a population of just over three million, is the List of U.S. states and territories by area, 13th largest by area, the List of U.S. states and territories by population, 30th most populous, and the List of U.S. states by population density, 11th least densely populated. Urban development is mostly concentrated in two regions: the Wasatch Front in the north-central part of the state, which includes the state capital, Salt Lake City, and is home to roughly two-thirds of the population; and Washington County, Utah, Washington County in the southwest, which has approximately 180,000 residents. Most of the western half of Utah lies in ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Living People
Purpose: Because living persons may suffer personal harm from inappropriate information, we should watch their articles carefully. By adding an article to this category, it marks them with a notice about sources whenever someone tries to edit them, to remind them of WP:BLP (biographies of living persons) policy that these articles must maintain a neutral point of view, maintain factual accuracy, and be properly sourced. Recent changes to these articles are listed on Special:RecentChangesLinked/Living people. Organization: This category should not be sub-categorized. Entries are generally sorted by family name In many societies, a surname, family name, or last name is the mostly hereditary portion of one's personal name that indicates one's family. It is typically combined with a given name to form the full name of a person, although several give .... Maintenance: Individuals of advanced age (over 90), for whom there has been no new documentation in the last ten ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]