The Atlantic Ocean is the second-largest of the world's five oceanic divisions, with an area of about 85,133,000 km2 (32,870,000 sq mi). It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for separating the New World of the Americas from the Old World of Afro-Eurasia.
The Cenozoic is Earth's current geological era, representing the last 66 million years of Earth's history. It is characterized by the dominance of mammals, birds, conifers, and angiosperms. It is the latest of three geological eras of the Phanerozoic Eon, preceded by the Mesozoic and Paleozoic. The Cenozoic 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.
Felidae is the family of mammals in the order Carnivora colloquially referred to as cats. A member of this family is also called a felid.
A mammoth is any species of the extinct elephantid genus Mammuthus. They lived from the late Miocene epoch into the Holocene until about 4,000 years ago, with mammoth species at various times inhabiting Africa, Europe, Asia, and North America. Mammoths are distinguished from living elephants by their spirally twisted tusks and in at least some later species, the development of numerous adaptions to living in cold environments, including a thick layer of fur.
North America is a continent in the Northern and Western Hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the west and south by the Pacific Ocean. The region includes the Bahamas, Bermuda, Canada, the Caribbean, Central America, Clipperton Island, Greenland, Mexico, Saint Pierre and Miquelon, Turks and Caicos Islands, and the United States.
The demographics of North Korea are determined through national censuses and international estimates. The Central Bureau of Statistics of North Korea conducted the most recent census in 2008, where the population reached 24 million inhabitants. The population density is 199.54 inhabitants per square kilometre, and the 2014 estimated life expectancy is 69.81 years. In 1980, the population rose at a near consistent, but low, rate. Since 2000, North Korea's birth rate has exceeded its death rate; the natural growth is positive. In terms of age structure, the population is dominated by the 15–64-year-old segment (68.09%). The median age of the population is 32.9 years, and the gender ratio is 0.95 males to 1.00 female. Since the early 1990s, the birth rate has been fairly stable, with an average of 2 children per woman, down from an average of 3 in the early 1980s.
The Pleistocene is the geological epoch that lasted from c. 2.58 million to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek πλεῖστος (pleîstos) 'most' and καινός 'new'.
The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch 3,000 miles in straight-line distance from the northernmost part of western Canada, to New Mexico in the southwestern United States. Depending on differing definitions between Canada and the U.S., its northern terminus is located either in northern British Columbia's Terminal Range south of the Liard River and east of the Trench, or in the northeastern foothills of the Brooks Range/British Mountains that face the Beaufort Sea coasts between the Canning River and the Firth River across the Alaska-Yukon border. Its southernmost point is near the Albuquerque area adjacent to the Rio Grande rift and north of the Sandia–Manzano Mountain Range. Being the easternmost portion of the North American Cordillera, the Rockies are distinct from the tectonically younger Cascade Range and Sierra Nevada, which both lie farther to its west.
The Americas, sometimes collectively called America, known initially as India Nova, are a landmass comprising the totality of North America and South America. The Americas make up most of the land in Earth's Western Hemisphere and comprise the New World.
The Vietnam War was a conflict in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. It was the second of the Indochina Wars and a major conflict of the Cold War. While the war was officially fought between North Vietnam and South Vietnam, the north was supported by the Soviet Union, China, and other countries in the Eastern Bloc, while the south was supported by the US and anti-communist allies. This made it a proxy war between the US and Soviet Union. It lasted almost 20 years, with direct US military involvement ending in 1973. The conflict spilled into the Laotian and Cambodian civil wars, which ended with all three countries becoming communist in 1975.
The first millennium of the anno Domini or Common Era was a millennium spanning the years 1 to 1000. The world population rose more slowly than during the preceding millennium, from about 200 million in the year 1 to about 300 million in the year 1000.
The United States had an official estimated resident population of 335,893,238 on Jan 1, 2024, according to the U.S. Census Bureau. This figure includes the 50 states and Washington, D.C. but excludes the population of five unincorporated U.S. territories as well as several minor island possessions. The United States is the third most populous country in the world, and the most populous in the Americas and the Western Hemisphere. The Census Bureau showed a population increase of 0.4% for the twelve-month period ending in July 2022, below the world average annual rate of 0.9%. The total fertility rate in the United States estimated for 2022 is 1.665 children per woman, which is below the replacement fertility rate of approximately 2.1. By several metrics, including racial and ethnic background, religious affiliation, and percentage of rural and urban divide, Illinois is the most representative of the larger demography of the United States.
The Ring of Fire is a tectonic belt of volcanoes and earthquakes.
The Pacific plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At 103 million km2 (40 million sq mi), it is the largest tectonic plate.
Canada ranks 36th by population among countries of the world, comprising about 0.5% of the world's total, with more than 40 million Canadians as of 2024. Despite being the second-largest country by total area, the vast majority of the country is sparsely inhabited, with most of its population south of the 55th parallel north. Just over 60 percent of Canadians live in just two provinces: Ontario and Quebec. Though Canada's overall population density is low, many regions in the south, such as the Quebec City–Windsor Corridor, have population densities higher than several European countries. Canada has six population centres with more than one million people: Toronto, Montreal, Vancouver, Calgary, Edmonton and Ottawa.
The Caribbean plate is a mostly oceanic tectonic plate underlying Central America and the Caribbean Sea off the northern coast of South America.
The extinct Borophaginae form one of three subfamilies found within the canid family. The other two canid subfamilies are the extinct Hesperocyoninae and extant Caninae. Borophaginae, called "bone-crushing dogs", were endemic to North America during the Oligocene to Pliocene and lived roughly 34—2.5 million years ago, existing for about 33.5 million years.
The geology of the Rocky Mountains is that of a discontinuous series of mountain ranges with distinct geological origins. Collectively these make up the Rocky Mountains, a mountain system that stretches from Northern British Columbia through central New Mexico and which is part of the great mountain system known as the North American Cordillera.
The geological history of the Earth follows the major geological events in Earth's past based on the geological time scale, a system of chronological measurement based on the study of the planet's rock layers (stratigraphy). Earth formed about 4.54 billion years ago by accretion from the solar nebula, a disk-shaped mass of dust and gas left over from the formation of the Sun, which also created the rest of the Solar System.
Larry D. Martin."Fossil history of terrestrial Carnivora". In John Gittleman,ed.,Carnivore Behavior,Ecology and Evolution, 1989,pp. 558–559.
