"non-avian dinosaur species were alive at the end of the Cretaceous and underwent sudden extinction after the Cretaceous–Paleogene extinction event. Alternatively, interpretation based on the fossil-bearing rocks along the Red Deer River in Alberta, Canada, supports the gradual extinction of non-avian dinosaurs; during the last 10 million years of the Cretaceous layers there, the number of dinosaur species seems to have decreased from about 45 to approximately 12. Other scientists have made the same assessment following their research. Several researchers support the existence of Paleocene non-avian dinosaurs. Evidence of this existence is based on the discovery of dinosaur remains in"
"until 66 million years when the Cretaceous–Paleogene extinction event occurred. While the Cretaceous is often referred to as the end of the age of dinosaurs, many new lifeforms appeared. This is the age of ""Tyrannosaurus rex"" and the ceratopsian dinosaurs (armoured and horned dinosaurs like ""Triceratops""). The abundant marine deposits of the North East coast of South Africa are of this age. There is also the hope of finding the rarest forms of vertebrates alive in this time period – the tiny mammals which would eventually dominate the planet after the Cretaceous extinction event. The Cretaceous is followed by the"
"Aptian extinction The Aptian extinction was an extinction event of the early Cretaceous Period. It is dated to c. 116 or 117 million years ago, in the middle of the Aptian stage of the geological time scale, and has sometimes been termed the mid-Aptian extinction event as a result. It is classified as a minor extinction event, rather than a major event like the famous Cretaceous–Paleogene extinction event that brought about the end of the ""age of dinosaurs"" and the Mesozoic Era. The Aptian event is most readily detected among marine rather than terrestrial fossil deposits. Nonetheless, ""From a palaeobotanical"
"specific age of 66.043 ± 0.011 Ma. The K–Pg boundary is associated with the Cretaceous–Paleogene extinction event, a mass extinction which destroyed a majority of the world's Mesozoic species, including all dinosaurs except for birds. Strong evidence exists that the extinction coincided with a large meteorite impact at the Chicxulub crater and the generally accepted scientific theory is that this impact triggered the extinction event. In 1980, a team of researchers consisting of Nobel Prize-winning physicist Luis Alvarez, his son, geologist Walter Alvarez, and chemists Frank Asaro and Helen Michel discovered that sedimentary layers found all over the world at"
"Jurassic The Jurassic (; from Jura Mountains) was a geologic period and system that spanned 56 million years from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period Mya. The Jurassic constitutes the middle period of the Mesozoic Era, also known as the Age of Reptiles. The start of the period was marked by the major Triassic–Jurassic extinction event. Two other extinction events occurred during the period: the Pliensbachian-Toarcian extinction in the Early Jurassic, and the Tithonian event at the end; however, neither event ranks among the ""Big Five"" mass extinctions. The"
"extinction event when both global biodiversity and alpha diversity (community-level diversity) were devastated. The world after the extinction was almost lifeless, deserted, hot, and dry. Ammonites, fishes, insects, and the tetrapods (cynodonts, amphibians, reptiles, etc.) remained rare and terrestrial ecosystems did not recover for 30 million years. Changhsingian In the geologic time scale, the Changhsingian or Changxingian is the latest age or uppermost stage of the Permian. It is also the upper or latest of two subdivisions of the Lopingian epoch or series. The Changhsingian lasted from to 251.902 million years ago (Ma). It was preceded by the Wuchiapingian and"
"Late Triassic The Late Triassic is the third and final of three epochs of the Triassic Period in the geologic timescale. The Triassic-Jurassic extinction event began during this epoch and is one of the five major mass extinction events of the Earth. The corresponding series is known as the Upper Triassic. In Europe the epoch was called the Keuper, after a German lithostratigraphic group (a sequence of rock strata) that has a roughly corresponding age. The Late Triassic spans the time between Ma and Ma (million years ago). The Late Triassic is divided into the Carnian, Norian and Rhaetian ages."
"Cretaceous–Paleogene extinction event The Cretaceous–Paleogene (K–Pg) extinction event, also known as the Cretaceous–Tertiary (K–T) extinction, was a sudden mass extinction of some three-quarters of the plant and animal species on Earth, approximately 66 million years ago. With the exception of some ectothermic species such as the leatherback sea turtle and crocodiles, no tetrapods weighing more than survived. It marked the end of the Cretaceous period and with it, the entire Mesozoic Era, opening the Cenozoic Era that continues today. In the geologic record, the K–Pg event is marked by a thin layer of sediment called the K–Pg boundary, which can"
"Cenozoic The Cenozoic Era () meaning ""new life"", is the current and most recent of the three Phanerozoic geological eras, following the Mesozoic Era and extending from 66 million years ago to the present day. The Cenozoic is also known as the ""Age of Mammals,"" because the extinction of many groups allowed mammals to greatly diversify so that large mammals dominated it. The continents also moved into their current positions during this era. Early in the Cenozoic, following the K-Pg extinction event, most of the fauna was relatively small, and included small mammals, birds, reptiles, and amphibians. From a geological"
"10 kilograms became extinct, and the age of the dinosaurs came to an end. The Cenozoic featured the rise of mammals as the dominant class of animals, as the end of the age of the dinosaurs left significant evolutionary vacuums. There are three divisions of the Cenozoic: Paleogene, Neogene and Quaternary. The Paleogene spans from the extinction of the non-avian dinosaurs, some 66 million years ago, to the dawn of the Neogene 23 million years ago. It features three epochs: Paleocene, Eocene and Oligocene. The Paleocene Epoch began with the K-T extinction event caused by the impact of a metorite"
"and much other fauna and flora. The die-off of the dinosaurs left unfilled ecological niches worldwide. The Paleocene ended with the Paleocene–Eocene Thermal Maximum, a geologically brief (~0.2 million year) interval characterized by extreme changes in climate and carbon cycling. The name ""Paleocene"" comes from Ancient Greek and refers to the ""old(er)"" (, ""palaios"") ""new"" (, ""kainos"") fauna that arose during the epoch. The K–Pg boundary that marks the separation between Cretaceous and Paleocene is visible in the geological record of much of the Earth by a discontinuity in the fossil fauna and high iridium levels. There is also fossil"
"Paleocene The Paleocene () or Palaeocene, the ""old recent"", is a geological epoch that lasted from about . It is the first epoch of the Paleogene Period in the modern Cenozoic Era. As with many geologic periods, the strata that define the epoch's beginning and end are well identified, but the exact ages remain uncertain. The Paleocene Epoch is bracketed by two major events in Earth's history. It started with the mass extinction event at the end of the Cretaceous, known as the Cretaceous–Paleogene (K–Pg) boundary. This was a time marked by the demise of non-avian dinosaurs, giant marine reptiles"
"Walter Alvarez and colleagues, links the extinction event at the end of the Cretaceous period to a bolide impact approximately 66 million years ago. Alvarez ""et al."" proposed that a sudden increase in iridium levels, recorded around the world in the period's rock stratum, was direct evidence of the impact. The bulk of the evidence now suggests that a bolide wide hit in the vicinity of the Yucatán Peninsula (in southeastern Mexico), creating the approximately Chicxulub Crater and triggering the mass extinction. Scientists are not certain whether dinosaurs were thriving or declining before the impact event. Some scientists propose that"
"the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. As with other geologic periods, the strata that define the start and end of the epoch are well identified, though their exact dates are slightly uncertain. The name ""Eocene"" comes from the Ancient Greek (""ēṓs"", ""dawn"") and (""kainós"", ""new"") and refers to the ""dawn"" of modern ('new') fauna that appeared during the epoch. The Eocene epoch is conventionally divided into early, middle, and late subdivisions. The corresponding rocks are referred to as lower, middle,"
"Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous epoch or Upper Cretaceous series, the Cretaceous period or system, and of the Mesozoic era or erathem. It spanned the interval from . The Maastrichtian was preceded by the Campanian and succeeded by the Danian (part of the Paleogene and Paleocene). At the end of this period, there was a mass extinction known as the Cretaceous–Paleogene extinction event, (formerly known as the Cretaceous–Tertiary extinction event). At this extinction event, many commonly recognized groups such as non-avian dinosaurs, plesiosaurs and mosasaurs, as"
"which new taxa came into play. The Rhaetian age was the final stage of the Triassic era's mass extinction, in succession to the Norian stage, and was last major disruption of life until the end-Cretaceous mass extinction. This stage of the Triassic is known for its extinction of marine reptiles, such as nothosaurs and shashtosaurs with the ichthyosaurs, similar to today's dolphin. This stage was concluded with the disappearance of many species that removed types of plankton from the face of the earth, as well as some organisms known for reef-building, and the pelagic conodonts. In addition to these species"
"Alvarez hypothesis The Alvarez hypothesis posits that the mass extinction of the dinosaurs and many other living things during the Cretaceous–Paleogene extinction event was caused by the impact of a large asteroid on the Earth. Prior to 2013, it was commonly cited as having happened about 65 million years ago, but Renne and colleagues (2013) gave an updated value of 66 million years. Evidence indicates that the asteroid fell in the Yucatán Peninsula, at Chicxulub, Mexico. The hypothesis is named after the father-and-son team of scientists Luis and Walter Alvarez, who first suggested it in 1980. In March 2010, an"
"creodonts, whales, primates, entelodonts, saber-toothed cats, mastodons and mammoths, three-toed horses, giant rhinoceros like ""Indricotherium"", the rhinoceros-like brontotheres, various bizarre groups of mammals from South America, such as the vaguely elephant-like pyrotheres and the dog-like marsupial relatives called borhyaenids and the monotremes and marsupials of Australia. Cenozoic The Cenozoic Era () meaning ""new life"", is the current and most recent of the three Phanerozoic geological eras, following the Mesozoic Era and extending from 66 million years ago to the present day. The Cenozoic is also known as the ""Age of Mammals,"" because the extinction of many groups allowed mammals to"
"was some sort of end-Carnian extinction, when several herbivorous archosauromorph groups died out, while the large herbivorous therapsids—the kannemeyeriid dicynodonts and the traversodont cynodonts—were much reduced in the northern half of Pangaea (Laurasia). These extinctions within the Triassic and at its end allowed the dinosaurs to expand into many niches that had become unoccupied. Dinosaurs became increasingly dominant, abundant and diverse, and remained that way for the next 150 million years. The true ""Age of Dinosaurs"" is during the following Jurassic and Cretaceous periods, rather than the Triassic. Triassic The Triassic () is a geologic period and system which spans"
"Triassic–Jurassic extinction event The Triassic–Jurassic extinction event marks the boundary between the Triassic and Jurassic periods, , and is one of the major extinction events of the Phanerozoic eon, profoundly affecting life on land and in the oceans. In the seas, a whole class (conodonts) and 23-34% of marine genera disappeared. On land, all archosaurs other than crocodylomorphs (Sphenosuchia and Crocodyliformes) and Avemetatarsalia (pterosaurs and dinosaurs), some remaining therapsids, and many of the large amphibians became extinct. About 42% of all terrestrial tetrapods went extinct. This event vacated terrestrial ecological niches, allowing the dinosaurs to assume the dominant roles in"
"extinction of the dinosaurs may have occurred rapidly in geologic terms, over thousands of years, rather than millions of years as had previously been supposed. Others continue to study alternative extinction causes such as increased volcanism, particularly the massive Deccan Traps eruptions that occurred around the same time, and climate change, checking against the fossil record. However, on March 4, 2010, a panel of 41 scientists agreed that the Chicxulub asteroid impact triggered the mass extinction. In his autobiography, Alvarez said, ""I think of myself as having had two separate careers, one in science and one in aviation. I've found"
"wide acceptance with regard to certain events in the distant past. One impetus for this change came from the publication of a historic paper by Walter and Luis Alvarez in 1980. This paper suggested that a asteroid struck Earth 66 million years ago at the end of the Cretaceous period. The impact wiped out about 70% of all species, including the dinosaurs, leaving behind the Cretaceous–Paleogene boundary (K–T boundary). In 1990, a candidate crater marking the impact was identified at Chicxulub in the Yucatán Peninsula of Mexico. Since then, the debate about the extinction of the dinosaurs and other mass"
"mass extinctions that on average extinguished half of all species. One of the largest mass extinctions to have affected life on Earth was the Permian-Triassic, which ended the Permian period 250 million years ago and killed off 90 percent of all species; life on Earth took 30 million years to recover. The cause of the Permian-Triassic extinction is still a matter of debate; the age and origin of proposed impact craters, i.e. the Bedout High structure, hypothesized to be associated with it are still controversial. The last such mass extinction led to the demise of the dinosaurs and coincided with"
"Toarcian turnover The term Toarcian turnover, alternatively the Toarcian extinction, the Pliensbachian-Toarcian extinction, or the Early Jurassic extinction, refers to the wave of extinctions that marked the end of the Pliensbachian stage and the start of the Toarcian stage of the Early Jurassic period, c. 183 million years ago. The Toarcian turnover was most strongly manifested in aquatic lifeforms, notably in mollusk groups like ammonites. Its reach was global in extent, as evidenced by research in European (peninsula of Peniche, Portugal) and Japanese waters, the Andean basin, the floor of the former Tethys Sea. Evidence points to anoxic bottom waters"
"the late Paleozoic. The Mesozoic (""middle life"") era lasted from 251 Ma to Ma. It is subdivided into the Triassic, Jurassic, and Cretaceous periods. The era began with the Permian–Triassic extinction event, the most severe extinction event in the fossil record; 95% of the species on Earth died out. It ended with the Cretaceous–Paleogene extinction event that wiped out the dinosaurs.. The Cenozoic (""new life"") era began at Ma, and is subdivided into the Paleogene, Neogene, and Quaternary periods. These three periods are further split into seven sub-divisions, with the Paleogene composed of The Paleocene, Eocene, and Oligocene, the Neogene"
"the extinction of tyrannosaurs and other non-avian dinosaurs is admitted to have happened far before, approximately 66 million years ago. However, the herbivore dinosaur in the short is a ceratopsian and it could be identified as a ""Monoclonius"". But it also could be a ""Centrosaurus"". Some scientists already have suggested that both genera, ""Monoclonius"" and ""Centrosaurus"", are synonyms. Specimens of both genera, whether or not synonymised with ""Centrosaurus"", are found in close stratigraphic ranges: from 77 million years ago (Ma) to 74.8 Ma for ""Monoclonius"" and from 76.5 Ma to 75.5 Ma for ""Centrosaurus"". Even if considered as separated genera"
"The Last Days of Dinosaurs (book) The Last Days of Dinosaurs (in Czech original ""Poslední dny dinosaurů"") is a science-fiction thriller from Czech writer and science promoter Vladimír Socha. Its story is about four audacious people who undergo a time travel to the very end of the Cretaceous period 66 million years ago. Not only must they find a way how to evade the Armageddon caused by the giant asteroid (Chicxulub) impact, they also have to save themselves from the dangerous theropod dinosaurs (like ""Tyrannosaurus"" or ""Dakotaraptor"") and even a mad scientist who wants to change the course of evolution"
"Permian–Triassic extinction event The Permian–Triassic (P–Tr or P–T) extinction event, colloquially known as the Great Dying, the End-Permian Extinction or the Great Permian Extinction, occurred about 252 Ma (million years) ago, forming the boundary between the Permian and Triassic geologic periods, as well as between the Paleozoic and Mesozoic eras. It is the Earth's most severe known extinction event, with up to 96% of all marine species and 70% of terrestrial vertebrate species becoming extinct. It is the only known mass extinction of insects. Some 57% of all biological families and 83% of all genera became extinct. Because so much"
"a boom of reptilian evolution on land as the first true dinosaurs evolved, as well as pterosaurs. By the end of the period the first gigantic dinosaurs had evolved and advanced pterosaurs colonised Pangaea's deserts. The climactic change, however, resulted in a large die-out known as the Triassic-Jurassic extinction event, in which all archosaurs (excluding ancient crocodiles), synapsids, and almost all large amphibians became extinct, as well as 34% of marine life in the fourth mass extinction event. The extinction's cause is debated. The Jurassic ranges from 200 million to 145 million years ago, and features three major epochs: Early"
"left them available as food for other survivors. This mass extinction is known as the Cretaceous–Paleogene extinction event. The nature of the event that caused this mass extinction has been extensively studied since the 1970s; at present, several related theories are supported by paleontologists. Though the consensus is that an impact event was the primary cause of dinosaur extinction, some scientists cite other possible causes, or support the idea that a confluence of several factors was responsible for the sudden disappearance of dinosaurs from the fossil record. The asteroid collision theory, which was brought to wide attention in 1980 by"
"extinction event brought the age of dinosaurs to a close. In the early Paleogene period between 63 and 52 Ma, the last volcanic rocks in the British Isles were formed. As North America and Greenland separated from Europe, the Atlantic Ocean slowly formed. This led to a chain of volcanic sites west of mainland Scotland including on Skye, the Small Isles and St. Kilda, in the Firth of Clyde on Arran and Ailsa Craig and at Ardnamurchan. Sea levels began to fall, and for the first time the general outline of the modern British Isles was revealed. At the beginning"
"epoch has begun, with the most abrupt and widespread extinction of species since the Cretaceous–Paleogene extinction event 66 million years ago. The term ""anthropocene"" is being used more frequently by scientists, and some commentators may refer to the current and projected future extinctions as part of a longer Holocene extinction. The Holocene–Anthropocene boundary is contested, with some commentators asserting significant human influence on climate for much of what is normally regarded as the Holocene Epoch. Other commentators place the Holocene–Anthropocene boundary at the industrial revolution and also say that ""[f]ormal adoption of this term in the near future will largely"
"Eocene–Oligocene extinction event The transition between the end of the Eocene (33.9 Ma) and the beginning of the Oligocene is marked by large-scale extinction and floral and faunal turnover (although minor in comparison to the largest mass extinctions). Most of the affected organisms were marine or aquatic in nature. They included the last of the ancient cetaceans, the Archaeoceti. This was a time of major climatic change, especially cooling, not obviously linked with any single major impact or any catastrophic volcanic event. One cause of the extinction event is speculated to be extended volcanic activity. Another speculation is that the"