Extinction is the termination of a taxon by the death of its last member. A taxon may become functionally extinct before the death of its last member if it loses the capacity to reproduce and recover. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" after a period of apparent absence.
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological species. A series of Regional Red Lists, which assess the risk of extinction to species within a political management unit, are also produced by countries and organizations.
The Late Cretaceous is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after creta, the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period.
Peacock bass or Brazilian tucunaré are large freshwater cichlids of the genus Cichla. These are diurnal predatory fishes native to the Amazon and Orinoco basins, as well as rivers of the Guianas, in tropical South America. They are sometimes referred to in English by their Brazilian name tucunaré or their Spanish name pavon. Despite the common name and their superficial similarity, they are not closely related to other fish known as bass, such as the North American largemouth bass.
The thicktail chub was a type of minnow that inhabited the lowlands and weedy backwaters of the Sacramento and San Joaquin Rivers in the Central Valley of California. It was once abundant in lowland lakes, marshes, ponds, slow-moving stretches of river, and, during years of heavy run-off, the surface waters of San Francisco Bay. The thicktail chub was one of the most common fish in California. Within Native American middens it represented 40% of the fish.
The Alvord cutthroat trout, Oncorhynchus clarkii alvordensis, was a subspecies of cutthroat trout. It was known only from Trout Creek in Oregon and Virgin Creek in Nevada, although it may have lived in several of the larger Alvord Basin streams during recent times. It was native to spring-fed creeks that ran down to Alvord Dry Lake in southeast Oregon, which was a large lake during the ice ages and an isolated drainage, part of the Great Basin today. This is one of the two cutthroat trout taxa considered extinct because all known populations are hybridized with rainbow trout which were introduced into streams in the Alvord basin in the 1920s, resulting in cutbows.
In the geologic timescale, the Olenekian is an age in the Early Triassic epoch; in chronostratigraphy, it is a stage in the Lower Triassic series. It spans the time between 251.2 Ma and 247.2 Ma. The Olenekian is sometimes divided into the Smithian and the Spathian subages or substages. The Olenekian follows the Induan and is followed by the Anisian.
The speckled smooth-hound is a houndshark of the family Triakidae. It is found on the continental shelf of the eastern Pacific, between latitudes 0° and 54° S, at depths between 16 and 50 m. It can reach a length of 130 cm (51 in). Collectively with certain other species of shark, it is known as "tollo".
The Mexican dace, or Mexican chub, is an extinct species of ray-finned fish in the family Cyprinidae. It was found only in Mexico, in the canals and streams of the Valley of Mexico. It is estimated to have become extinct circa 1983. The extinction of this species coincided with the drying of water bodies in the valley. This drying was a result of the increasing demands placed on the water resources of the valley by agriculture, as well as by the growth of Mexico City and its suburbs.
The Durango shiner is an extinct species of freshwater fish of the family Cyprinidae. It was found only in Mexico. The Durango shiner was native to the Rio Tunal, which forms the headwaters of the San Pedro Mezquital River, a Pacific slope river rising near Durango City, Durango, Mexico. It was taken there only in 1951 and 1961. Its closest relatives were the yellow shiner and the Ameca shiner.
The Late Pleistocene to the beginning of the Holocene saw numerous extinctions of predominantly megafaunal (large) animal species, which resulted in a collapse in faunal density and diversity across the globe. The extinctions during the Late Pleistocene are differentiated from previous extinctions by the widespread absence of ecological succession to replace these extinct megafaunal species, and the regime shift of previously established faunal relationships and habitats as a consequence. The timing and severity of the extinctions varied by region and are thought to have been driven by varying combinations of human and climatic factors. Human impact on megafauna populations is thought to have been driven by hunting ("overkill"), as well as possibly environmental alteration. The relative importance of human vs climatic factors in the extinctions has been the subject of long-running controversy.
The Paleocene, or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek παλαιός palaiós meaning "old" and the Eocene Epoch, translating to "the old part of the Eocene".
Maple Creek is an unincorporated community in Humboldt County, California. It is located 9 miles (14 km) south-southeast of Korbel, at an elevation of 528 feet.
The San Pedro Mezquital River is a river of Nayarit, Mexico.
The Dawson Creek Kodiaks were a Junior ice hockey team from Dawson Creek, British Columbia, Canada. They are former members of the Peace-Cariboo Junior Hockey League.
West Branch Mahantango Creek is a tributary of Mahantango Creek in Snyder County and Juniata County, in Pennsylvania, in the United States. It is approximately 18 miles (29 km) in length. The creek starts on Shade Mountain in Snyder County. It ends at its confluence with Mahantango Creek. Most of the land in the watershed is devoted to forest or agriculture. Trout and minnows have been observed in the creek, which is stocked with trout. A covered bridge was built over it in 1908.
HD 97413 is a binary star located in the southern constellation Centaurus. The system has a combined magnitude of 6.27, placing it near the limit for naked eye visibility. Based on parallax measurements from the Gaia spacecraft, the system is located 320 light years away from the Solar System.
The Cretaceous–Paleogene (K–Pg) extinction event, also known as the Cretaceous–Tertiary(K–T)extinction, was a sudden mass extinction of three-quarters of the plant and animal species on Earth, approximately 66 million years ago. The event caused the extinction of all non-avian dinosaurs. Most other tetrapods weighing more than 25 kilograms also became extinct, with the exception of some ectothermic species such as sea turtles and crocodilians. It marked the end of the Cretaceous period, and with it the Mesozoic era, while heralding the beginning of the Cenozoic era, which continues to this day.
The Bland Creek, a mostly–perennial river that is part of the Lachlan sub-catchment of the Murrumbidgee catchment within the Murray–Darling basin, is located in the South West Slopes, and Riverina regions of New South Wales, Australia. The Bland Creek is only connected to the Murray Darling basin when both the Lachlan and Murrumbidgee Rivers are in flood.
The cobble skink in the family Scincidae is a skink species endemic to New Zealand, found only on a single small stretch of stony beach at Granity, on the West Coast. In 2016 it was on the brink of extinction, with declining numbers and a threatened habitat, and all known individuals were captured and taken to Auckland Zoo.
