Permian Mass Extinction Essay

“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…”

Gerta Keller, professor of geosciences at Princeton University, has recently conducted research on the Chicxulub asteroid in which she analyzed new core samples taken from the asteroid site (Botzer 2004). These samples indicate that the impact that occurred at Chicxulub actually predated the mass extinction of the dinosaurs, which occurred at the Cretaceous-Tertiary boundary about sixty-five million years ago. Keller claims that the Chicxulub impact occurred approximately 300,000 years before the extinction (Keller 2004). Although previous researchers estimated that the Chicxulub asteroid was the cause of the extinctions, there had always been doubts about the exact age and size of the crater, and about the origin of the “mega tsunami deposits” that were located within the crater (Keller 2004). The focus of Keller’s recent research was on finding some answers to these questions. To do so she analyzed Cretaceous limestone, dolomite, and anhydrite deposits as the site of the Chicxulub crater (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 Great Dying” was the largest mass extinction ever recorder in the Earth’s history. It was the death of approximately 90% of all living species, such as, the trilobites, sea scorpions, and coral dating back to 254 million years ago (Randall). It is suspected that the eruption of many volcanoes in the Siberian Traps was the fallout of these species because the eruption killed off almost all plant life, leaving nothing for the animals alive. However, researchers have found new evidence to suggest that acid rain was the cause for this destruction (Randall).

There were multiple issues identified in opposition to this claim, the first being the lack of evidence for contemporaneity between the arrival of humans with the extinction of the megafauna. Without consensus on these two time periods inferences about the cause of megafaunal extinction cannot be made. Judith Field suggests that the site at Cuddie Springs demonstrates long periods of co-habitation between humans and now extinct megafauna, which generates issues in the rapid extinction aspect of Flannery’s hypotheses (“Taming the Fire”, 1998). In addition Bowman (1998) also proposes the evidence for primarily human induced megafaunal extinction is unsubstantial and possibly caused by numerous factors including climate and habitat changes (pp.

It is most likely that a simultaneous occurrence of the different global environmental changes was responsible for ending the Permian period, and the lives of 96% of species. Each environmental issue is a major geological event, and amplified the other events, leading to catastrophic environmental situation, in which barely any life could survive.

out (Bagley, 2014). This was the closer of the Permian-Triassic period. This means that the rest

Since the 1980s the most popular theory for why dinosaurs became extinct was because of a meteor, but many people are skeptical of whether or not the meteor was the only factor in the extinction of the dinosaurs. In Stephen Brusatte’s “What Killed the Dinosaurs,” Dr. Brusatte talks about how the mystery of the extinction of the dinosaurs was a hug influence on his life and caused him to become what he is today. As a teenager Brusatte had a chance to talk to Walter Alvarez, the man who proposed the idea of a meteor being the cause for the extinction of the dinosaurs. Alvarez was able to come up with this hypothesis by examining the clay band between the Cretaceous period and the Paleogene period. The Cretaceous period was a time when the Earth had a surplus amount of dinosaurs and the Paleogene period was the time period directly after the Cretaceous period where dinosaurs had become extinct. When Alvarez studied the clay band he had discovered that the band was saturated in iridium which is an element common on meteors and asteroids. This led him to believe that a meteor may have led to the downfall of the dinosaurs.

The Permian (alongside the Paleozoic) finished with the Permian– Triassic annihilation occasion, the biggest mass eradication in Earth's history, in which almost 90% of marine species and 70% of earthbound species kicked the bucket out. It would bring great into the Triassic for life to recoup from this catastrophe. Recuperation from the Permian– Triassic termination occasion was extended; ashore, biological communities took 30 million years to recover.

Although many people seem to have an understanding or guess as to how the dinosaurs and similar species may have become extinct around this time period, their are many theories out there suggesting otherwise. So in light of that my question is , What mite have been the primary cause or ( causes ) of the Cretaceous-Tertiary Mass extinction ?. This particular question interested me primarily on the fact that it not only took away many species from earth, but also the many different theories that associate with this mass extinction. Just as quick as these species were taken from the earth , their origin for their demise is just as important.

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.

The dinosaurs appeared after the greatest mass extinction event occurred. This is known as the Permian-Triassic extinction. It has been estimated to have occurred around two hundred and fifty million years ago. (6) It is also known as the Great Dying with over ninety percent of species dying off, leaving the Earth essentially a wasteland. It led to the extinction of “57% of all families, 83% of all genera and 90% to 96% of all species. 53% of marine families, 84% of marine genera, about 96% of all marine species and an estimated 70% of land species, including insects.”(7) By the late-Permian, global temperatures were very hot, with them being the highest ever on the planet.

The end-Triassic or Triassic-Jurassic extinction event occurred around 200 million years ago is and thought by numerous have helped dinosaurs to be the dominant species on earth for 135 million years. It additionally finished life for generally 50% of all species that were available around then. Until this event, mammal like animals known as therapsids were much more than the ancestors of the dinosaurs, known as archosaurs. The dinosaurs survived better compared to the early proto-vertebrates, and this extinction event may have altogether tipped it to support them clarifies #########. Of the Big Five, the Triassic-Jurassic extinction event has the least number of current researches. Its cause stays under debate,

A new study proposes the possibility that the minor mass extinction event on Earth about 2.59 million years ago could have been a result from a supernova explosion. It is believed that cosmic rays from a supernova could have potentially altered the climate and led to the minor mass extinction towards the end of the Pliocene epoch and at the beginning of the Pleistocene. Researchers ran computer simulations of supernovas and focused on how the affects could have changed Earth’s climate and biosphere. Supernovas are either created from a star that runs out of fuel or a white dwarf that steals matter from a neighboring star and crosses a mass threshold. Researchers believe that for a supernova to change the climate conditions of Earth and cause

Dinosaur extinction: An analysis of events and theories that possibly led to the dinosaurs' demise.