Cretaceous-Triassic Extinction Research Paper

“A minority disputes this theory, arguing that other events-such as volcanic eruptions, sea-level changes or a series of impacts-were to blame for the spectacular loss of species that occurred at the transition between the Cretaceous and Tertiary periods…”

The Permian mass extinction occurred 251Ma and is recognised as having the largest volcanic eruption as one of the main antagonists to the event, it is also responsible for ~96% of all species to be wiped out. The main theories for the Permian event are the Siberian traps and the possibility of an impact event but the latter is widely disregarded.

The fossil deposits at the Chicxulub site suggest that the mineral layer in the crater was deposited after the impact, but before the extinction of the dinosaurs and other species. Keller proposes two possible explanations for this. The first explanation is that the sediments were deposited as the backwash of a giant tsunami that occurred after the impact (Keller 2004).

8. The periods in which there were mass extinctions are Permian – volcanic eruptions which spewed lava and put CO2 into the air which warmed the climate an estimated 6 degrees Celsius. The resulting of oxygen deficiency. And Cretaceous – asteroid or comet

The main dinosaurs that died off were Sauropod dinosaurs, long necked, four legged dinosaurs, and stegosauridae, class holding Stegosaurus. Other species that died include ammonites, similar to the living animals called nautilus, many marine reptiles, and bivalves, relatable to modern mollusca. Not much is known about this extinction. It is mainly linked to climate change. So far, no connection to volcanic activity or an asteroid has been made. This extinction gave way to the Cretaceous Period.

A mass extinction is an event in which at least 25-75% of species in the global environment are eradicated in a short period of time. Where as a regional extinction event is when the extinction is confined to a specific zone. Five mass extinctions have occurred throughout time, two of the most well known of these are the Permian and Cretaceous extinction events.

this mass extinction is what brought us the jurassic period, and from the Jurassic period, or the

The Permian mass extinction, that struck about 250 million years ago, caused a mass extinction of reef and shallow water communities. Groups that lived on the seafloor and filtered organic material from the water for nourishment suffered the greatest extinction. Those include corals, shelled in-vertebrates, and a variety of sea lilies. Others marine groups includes trilobites, zooplankton and snails. Even though these species died in the water, living organisms on land were not much better off. Terrestrial vertebrates and insects both experienced a big loss in each of their groups. Also suffering a big loss was the insect family due to the lack of plant life and food. Seventy Eight percent of reptiles became extinct and sixty seven percent of the amphibian family became extinct during this time period.

The cretaceous-tertiary (KT) boundary extinction happened approximately sixty five million years ago. Sixty to eighty percent of all living species became extinct at this boundary (Raup 1988). The KT extinction was indeed a mass extinction event. Mass extinctions are periods in Earth's history when extremely large numbers of species die out simultaneously or within a limited time frame. The most severe mass extinction ever occurred at the end of the Permian period when 96% of all species died out. The K-T mass extinction obliterated almost all the large vertebrates on Earth, on land, at sea, and in the air (all dinosaurs, plesiosaurs, mosasaurs, and pterosaurs) suddenly became extinct at the end of the Cretaceous Period. At the same time, most

The first thing to know about this particular mass extinction is the species that inhibited the earth

The End Cretaceous impact hypothesis states that an asteroid impact on the earth caused the extinction. The evidence that supports this hypothesis include the crater found in the Yucatan Peninsula, the rare metal Iridium, and fractured “shocked quartz” crystals that have been shown to cause high-energy explosions. The End Cretaceous flood volcanism hypothesis states that a giant volcano eruption, or a series of volcano eruptions caused the extinction The evidence that supports this hypothesis includes immense lava flow, and volcano explosions, which happen to exposed iridium.

Ever since the history of Earth has been studied using fossil records, extinctions have always been the object of fascination and interest, particularly the mass extinctions that occurred throughout Earth's history. A mass extinction can be caused by disruptive global environmental changes, where large numbers of species have become extinct (Urry et al. 2008). There have been five major extinctions documented based on fossil records over the past 500 million years, but the Cretaceous (KT boundary extinction – a name that meant it began the Tertiary era) extinction caught a lot of

There have been five well known extinctions on this earth. The one most well known is the mass extinction that ended the dinosaurs. Mass extinction is often described as the elimination of a large number of species in a short period of time. Despite what many think, the elimination of species is almost commonplace at this point. The Earth is currently in the middle of a sixth mass extinction, and it’s been caused by the human race.

Over 98% of all organisms that have lived on Earth are now extinct. A mass extinction event occurs when a large number of species die out within a small time frame (relative to the age of Earth). Mass extinctions are intensively studied for both cause and effect, as there is usually room for debate regarding catalysts that precede the extinction and the massive influx of new biological species that follows. There have been five major mass extinctions, dubbed the “Big Five,” that have wiped out at least 50% of the species living at those times. The most well known mass extinction of the Big Five, with the decimation of every species of non-avian dinosaur, is the Cretaceous-Paleogene

These techniques led to the discovery of the boundary between the two eras. A single thin layer of clay found within predominantly limestone rocks established this. By comparing the marine life found in, above, and below the clay, the marine life, like the dinosaurs, had been terribly affected by the extinction event. The percentage of life in the upper layers was dramatically lower than that in the lower. This was far more compelling than what was suggested by dinosaur’s fossils.