Introduction
The Permian-Triassic extinction event is undoubtedly the largest extinction event the Earth has ever seen. While evidence shows that it occurred over a great amount of time, it was effective in causing the extinction of an incredibly large portion of life on Earth. To such an extent that it took millions of years before any large amounts of biodiversity occurred again. This is why it is also referred to as the ‘Great Dying’.
This paper will will analyze the survivability of terrestrial vertebrates compared to that of terrestrial invertebrates during the Permian-Triassic Extinction Event. It will discuss the extent of the extinction event in terms of numbers that terrestrial vertebrates and invertebrates went extinct/suffered losses, as well as how the surviving taxa survived, adapted, and evolved.
The Permian-Triassic extinction statistics and possible causes:
The Permian-Triassic extinction occurred around 252 million years ago, causing the end of about 96% of marine life and around 70% of terrestrial vertebrate life that existed at that time (Lecture 29. slide 5). Overall, the event caused 83% of all genera to go extinct. This event led to an incredibly long recovery period that took millions of years for life to regain a sense of biodiversity. While many niches in the terrestrial ecosystem were left empty, they eventually were filled by surviving creatures that adapted and evolved. The extinction event is suggested to have lasted over the course of millions of years, with different genera going extinct at different times.
The specific/primary cause for the Permian-Triassic Extinction event is still in contention by several researchers, but is generally agreed on to be the result of several ‘pulses’, or miniature...
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...turwissenschaften, Volume 97, Issue 2
4.) Jessica Amber Camp (2010), Morphological variation and disparity in Lystrosaurus (Therapsida: Dicynodontia), University of Iowa
5.) Peter D. Wardotha, Roger Black, Michiel O. De Kock, Douglas E. Erwin, Geoffrey H. Garrison, Joseph L. Kirschvink, Roger Smith (2005), Abrupt and Gradual Extinction Among Late Permian Land Vertebrates in the Karoo Basin , South Africa, Science 4, Vol. 307, no. 5710, 709-714 , DOI: 10.1126/science.1107068
6.)Jörg Fröbisch(2013), Vertebrate diversity across the end-Permian mass extinction — Separating biological and geological signals(pp. 50–61) , Palaeogeography, Palaeoclimatology, Palaeoecology
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7.) M. J. Benton, V. P. Tverdokhlebov , M. V. Surkov (2004), Ecosystem remodelling among vertebrates at the Permian–Triassic boundary in Russia),Nature 432, 97-100, doi:10.1038/nature02950
In this paper Martin is arguing that late quaternary or near time extinctions where caused by human activity or as he calls it “overkill”. Martin recognizes that there have been many forces that have triggered extinctions in the planet on the past but disagrees with the idea that near time extinctions where caused by some commonly believed causes like climate change, disease or nutrient shortage. He argues that the arrival of humans to different continents, islands and the subsequent excessive hunting, the introduction of diseases and other competitors and predators was the cause of extinction of a great number of species “As our species spread to various continents we wiped out their large
1) Carroll, R. L. 1988. Vertebrate Paleontology and Evolution. W. H. Freeman and Company, New York.
The question of what caused the extinction of megafauna during the Late Pleistocene period is one that archaeologists have struggled to answer for decades, but why should it matter? Discovering with certainty the cause of megafaunal extinction would simultaneously prove or disprove any of the proposed implications of each existing theory regarding this massive extinction.
The Permian-Triassic Extinction is a mass extinction that occurred between the Permian and Triassic geologic time periods approximately 250 million years ago; it is the deadliest of all extinctions that have occurred on Earth. In addition, during the Permian-Triassic extinction the continents of today existed as one supercontinent known as Pangaea. This was the first time in history where continental or land mass exceeded that of the ocean. This was also before dinosaurs of the Triassic period roamed Earth, during this time animals such as the therapsids, and Synapsids such as the Pelycosaurs, insects and amphibians also occupied Earth. Fauna that existed during the Permian period includes Gymnosperms, or seed producing plants such as the Conifers. Other animals that existed during this time include marine life such as brachiopods (clams), bryozoans (coral-like skeletons), bony fish and sharks, as well as crinoids (sea urchin like creatures). According to National Geographic, about 90 percent of all the animals and fauna of this period perished, the marine life was hit the hardest wi...
This breaking up of the mega continent of Pangaea allowed for more diversification of plant species and as the continents continued to break apart, plant life became even more diversified. As the continents shifted and moved from one area of the ocean to another the climates began to change drastically which allowed for plant and dinosaur species both to begin adapting to suit their new ecosystems. All the water that was produced by the split of Pangaea gave the previously hot and dry climate a more humid and drippy subtropical weather. Dry deserts took on a greener look. Before the Mesozoic Era, livings things were confined to only surviving in the oceans. It was not until the Jurassic Period that livings things evolved the capability of living on the land rather than just the ocean. Towards the beginning of the Jurassic, plant life evolved from Bryophytes, the low-growin...
The debate of whether dinosaurs were cold blooded or warm blooded has been ongoing since the beginning of the century. At the turn of the century scientists believed that dinosaurs had long limbs and were fairly slim, supporting the idea of a cold blooded reptile. Recently, however, the bone structure, number or predators to prey, and limb position have suggested a warm blooded species. In addition, the recent discovery of a fossilized dinosaur heart has supported the idea that dinosaurs were a warm blooded species. In this essay, I am going to give supporting evidence of dinosaurs being both warm and cold blooded. I will provide background information on the dinosaur that was discovered and what information it provides scientists.
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Han, J., Zhang, Z. F., & Liu, J. N. (2008). A preliminary note on the dispersal of the Cambrian Burgess Shale-type faunas. Gondwana Research, (1), 269-276. doi:10.1016/j.gr.2007.09.001
“Sex, Drugs, Disasters, and the Extinction of Dinosaurs” is written by Stephen Jay Gould, professor of geology and zoology at Harvard. This essay is one of more than a hundred articles on evolution, zoology, and paleontology published by Gould in national magazines and journals. It tells about scientific proposals for the extinction of dinosaurs – a confusing but an exciting problem that humanity tries to solve. By analyzing and describing each of the claims for the reptiles’ demise – sex, drugs, and disasters – Gould differentiates bad science from good science and explains what makes some theories silly speculations, while the other, a testable hypothesis.
The most significant event of the Cretaceous era came at its end. Nearly 65 million years ago, the second most severe mass extinction in earth’s history occurred. This resulted in the loss of around 80% of species living at the time. Though nowhere near as severe as the end-Permian mass extinction, the end-Cretaceous extinction is the most well known mass extinction event. This is due to the violent event that caused it the extinction, as well as the chapter of earth’s history that it closed: the Dinosaurs. The Cretaceous Event ( often shortened to K-T event) Of the animals that were killed off were the flying reptiles (pterosaurs) and the last few mosasaurs and plesiosaurs, both early marine reptiles. Many mollusks and species of microscopic plankton were killed. Terrestrial plants suffered mass extinction as well. Almost 60% of terrestrial plants were lost. This led to high extinction rates among insect populations, especially insects that were highly specialized to feed on just a few types of plants had it the worst. It took approximately 9 million years for the global insect populations to recover from the Cretaceous extinction. Immediately after the extinction, the earth saw an explosion of short term species who respond well to fire, or other external disturbance. Evidence of the catastrophe comes from a thin rock layer deposited worldwide just after the impact. It is dominated by fossil plants whose descendants recover quickly after fires of other disturbances, such as Fire Weed in Alaska. The causes of the Cretaceous extinction are still being debated by paleontologists. Scientists agree that the main cause of the extinction was a...
Several mass extinctions have occurred during the Earth’s history. The Cretaceous – Tertiary Boundary (K-T) Extinction caused the loss of at least three-quarters of all species known at that time including the dinosaurs. The cause of this mass extinction is a controversial subject among scientists but the fossil evidence of it’s occurrence is abundant.
Over the past century, the Burgess Shale has revealed important information about the development of earth’s history. The excavation of the Burgess Shale formation provided evidence for what was once just a theory in evolution. The taphonomic findings of the Burgess Shale have played a significant role in understanding the large diversity that resulted from the Cambrian explosion, advancing the study of evolutionary assemblages for Paleontologists worldwide.
seems like it happened so sudden, as geologic time goes, that almost all the dinosaurs
The discovery that birds are a type of dinosaur showed that dinosaurs in general are not, in fact, extinct as is commonly stated.[156] However, all non-avian dinosaurs as well as many groups of birds did suddenly become extinct approximately 66 million years ago. It has been suggested that because small mammals, squamata and birds occupied the ecological niches suited for small body size, non-avian dinosaurs never evolved a diverse fauna of small-bodied species, which led to their downfall when large-bodied terrestrial tetrapods were hit by the mass extinction event.[157] Many other groups of animals also became extinct at this time, including ammonites (nautilus-like mollusks), mosasaurs, plesiosaurs, pterosaurs, and many groups of mammals.[9] Significantly, the insects suffered no discernible population loss, which 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.[158][159][160]
Almost 23% of all families, 48% of all genera (20% of marine families and 55% of marine genera) and 70% to 75% of all species went extinct (Beaz). Although the cause of this mass extinction is debatable, many speculate that global warming was the killer. Because Pangea was breaking up into Laurasia and Gondwanaland, there was widespread volcanic activity caused by the rifting, increasing atmospheric carbon dioxide. The massive release of this greenhouse gas increased global air temperatures and resulted in acidified oceans along with rising sea levels. If this is the case, the life in the ocean would have died at a significant rate. Many families of brachiopods, gastropods, bivalves, and marine reptiles became extinct (Rafferty). An important trace fossil known as the phylloceratid ammonoid was able to survive, and they gave rise to the explosive radiation of cephalopods later in the Jurassic Period, as well as evolved into many different forms during the later Cretaceous (End Triassic Extinction). This extinction event ranks fourth in severity of the five major extinction events over geologic history