|
Paleontology In The United States
Paleontology in the United States refers to paleontological research occurring within or conducted by people from the United States. Paleontologists have found that at the start of the Paleozoic era, what is now "North" America was actually in the southern hemisphere. Marine life flourished in the country's many seas. Later the seas were largely replaced by swamps, home to amphibians and early reptiles. When the continents had assembled into Pangaea drier conditions prevailed. The evolutionary precursors to mammals dominated the country until a mass extinction event ended their reign. The Mesozoic era followed and the dinosaurs began their rise to dominance, spreading into the country before Pangaea split up. During the latter Jurassic Morrison Formation dinosaurs lived in the western states. During the Cretaceous, the Gulf of Mexico expanded until it split North America in half. Plesiosaurs and mosasaurs swam in its waters. Later it began to withdraw and the western states were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Map Of USA
The cartography of the United States is the history of surveying and creation of maps of the United States. Maps of the New World had been produced since the 19th century. The history of cartography of the United States begins in the 18th century, after the declared independence of the thirteen original colonies on July 4, 1776, during the American Revolutionary War (1776–1783) celebrating victory. Later, Samuel Augustus Mitchell published a map of the United States in 1850. The ''National Program for Topographic Mapping'' was initiated in 2001 by the United States Geological Survey. See also * Geography of the United States * Territorial evolution of the United States * United States National Grid * United States territorial acquisitions *Cartography of New York City The cartography of New York City is the creation, editing, processing and printing of maps that depict the islands and mainland that now comprise New York City and its immediate environs. The earliest survi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of the Mesozoic, Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic magmatic province, Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread Anoxic event, oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar, Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Creodonta
Creodonta ("meat teeth") is a former order of extinct carnivorous placental mammals that lived from the early Paleocene to the late Miocene epochs in North America, Europe, Asia and Africa. Originally thought to be a single group of animals ancestral to the modern Carnivora, this order is now usually considered a polyphyletic assemblage of two different groups, the Oxyaenids and the Hyenodonts, not a natural group. Oxyaenids are first known from the Palaeocene of North America, while hyaenodonts hail from the Palaeocene of Africa. Creodonts were the dominant carnivorous mammals from , peaking in diversity and prevalence during the Eocene. The first large, obviously carnivorous mammals appeared with the radiation of the oxyaenids in the late Paleocene. During the Paleogene, "creodont" species were the most abundant terrestrial carnivores in the Old World. In Oligocene Africa, hyaenodonts were the dominant group of large flesh-eaters, persisting until the middle of the Miocene. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horse
The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature, ''Eohippus'', into the large, single-toed animal of today. Humans began domesticating horses around 4000 BCE, and their domestication is believed to have been widespread by 3000 BCE. Horses in the subspecies ''caballus'' are domesticated, although some domesticated populations live in the wild as feral horses. These feral populations are not true wild horses, as this term is used to describe horses that have never been domesticated. There is an extensive, specialized vocabulary used to describe equine-related concepts, covering everything from anatomy to life stages, size, colors, markings, breeds, locomotion, and behavior. Horses are adapted to run, allowing them to quickly escape predators, and po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camel
A camel (from: la, camelus and grc-gre, κάμηλος (''kamēlos'') from Hebrew or Phoenician: גָמָל ''gāmāl''.) is an even-toed ungulate in the genus ''Camelus'' that bears distinctive fatty deposits known as "humps" on its back. Camels have long been domesticated and, as livestock, they provide food (milk and meat) and textiles (fiber and felt from hair). Camels are working animals especially suited to their desert habitat and are a vital means of transport for passengers and cargo. There are three surviving species of camel. The one-humped dromedary makes up 94% of the world's camel population, and the two-humped Bactrian camel makes up 6%. The Wild Bactrian camel is a separate species and is now critically endangered. The word ''camel'' is also used informally in a wider sense, where the more correct term is "camelid", to include all seven species of the family Camelidae: the true camels (the above three species), along with the "New World" camelids: the llama, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant species of mammals have been described divided into 29 orders. The largest orders, in terms of number of species, are the rodents, bats, and Eulipotyphla (hedgehogs, moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla ( cetaceans and even-toed ungulates), and the Carnivora (cats, dogs, seals, and others). In terms of cladistics, which reflects evolutionary history, mammals are the only living members of the Synapsida (synapsids); this clade, together with Saur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cenozoic Era
The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configuration of continents. It is the latest of three geological eras since complex life evolved, preceded by the Mesozoic and Paleozoic. It started with the Cretaceous–Paleogene extinction event, when many species, including the non-avian dinosaurs, became extinct in an event attributed by most experts to the impact of a large asteroid or other celestial body, the Chicxulub impactor. The Cenozoic is also known as the Age of Mammals because the terrestrial animals that dominated both hemispheres were mammalsthe eutherians (placentals) in the northern hemisphere and the metatherians (marsupials, now mainly restricted to Australia) in the southern hemisphere. The extinction of many groups allowed mammals and birds to greatly diversify so that l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous Mass Extinction
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now- extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hell Creek Formation
The Hell Creek Formation is an intensively studied division of mostly Upper Cretaceous and some lower Paleocene rocks in North America, named for exposures studied along Hell Creek, near Jordan, Montana. The formation stretches over portions of Montana, North Dakota, South Dakota, and Wyoming. In Montana, the Hell Creek Formation overlies the Fox Hills Formation. The site of Pompeys Pillar National Monument is a small isolated section of the Hell Creek Formation. In 1966, the Hell Creek Fossil Area was designated as a National Natural Landmark by the National Park Service. It is a series of fresh and brackish-water clays, mudstones, and sandstones deposited during the Maastrichtian and Danian (respectively, the end of the Cretaceous period and the beginning of the Paleogene) by fluvial activity in fluctuating river channels and deltas and very occasional peaty swamp deposits along the low-lying eastern continental margin fronting the late Cretaceous Western Interior Seaway. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mosasaurs
Mosasaurs (from Latin ''Mosa'' meaning the 'Meuse', and Greek ' meaning 'lizard') comprise a group of extinct, large marine reptiles from the Late Cretaceous. Their first fossil remains were discovered in a limestone quarry at Maastricht on the Meuse in 1764. They belong to the order Squamata, which includes lizards and snakes. Mosasaurs probably evolved from an extinct group of aquatic lizards known as aigialosaurs in the Earliest Late Cretaceous with 42 described genera. During the last 20 million years of the Cretaceous period (Turonian–Maastrichtian ages), with the extinction of the ichthyosaurs and pliosaurs, mosasaurs became the dominant marine predators. They themselves became extinct as a result of the K-Pg event at the end of the Cretaceous period, about 66 million years ago. Description Mosasaurs breathed air, were powerful swimmers, and were well-adapted to living in the warm, shallow inland seas prevalent during the Late Cretaceous period. Mosasaurs were so we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plesiosaurs
The Plesiosauria (; Greek: πλησίος, ''plesios'', meaning "near to" and ''sauros'', meaning "lizard") or plesiosaurs are an order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared in the latest Triassic Period, possibly in the Rhaetian stage, about 203 million years ago. They became especially common during the Jurassic Period, thriving until their disappearance due to the Cretaceous–Paleogene extinction event at the end of the Cretaceous Period, about 66 million years ago. They had a worldwide oceanic distribution, and some species at least partly inhabited freshwater environments. Plesiosaurs were among the first fossil reptiles discovered. In the beginning of the nineteenth century, scientists realised how distinctive their build was and they were named as a separate order in 1835. The first plesiosaurian genus, the eponymous ''Plesiosaurus'', was named in 1821. Since then, more than a hundred valid s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gulf Of Mexico
The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States; on the southwest and south by the Mexico, Mexican States of Mexico, states of Tamaulipas, Veracruz, Tabasco, Campeche, Yucatan, and Quintana Roo; and on the southeast by Cuba. The Southern United States, Southern U.S. states of Texas, Louisiana, Mississippi, Alabama, and Florida, which border the Gulf on the north, are often referred to as the "Third Coast" of the United States (in addition to its Atlantic and Pacific Ocean, Pacific coasts). The Gulf of Mexico took shape approximately 300 million years ago as a result of plate tectonics.Huerta, A.D., and D.L. Harry (2012) ''Wilson cycles, tectonic inheritance, and rifting of the North American Gulf of Mexico continental margin.'' Geosphere. 8(1):GES00725.1, first p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
