|Calibrations and Answer Keys
Average Calibration Word Count = 147
High Quality Calibration
The Permo-Triassic mass extincition was a very large extinction event in Earth history. In fact it was the largest of all recorded extinction events, but it is not the most famous extinction event. The most famous mass extinction was the Cretaceous-Tertiary extinction because that is the event that brought an end to the Age of the Dinosaurs.
Both mass extinctions caused many organisms to parish, but they were caused by different circumstances. The Permo-Triassic extinction was caused by they formation of Pangaea over the South Pole. This lead to global cooling and the elimination of a lot of shallow marine environments. The Cretaceous-Tertiary event was caused by an asteroid impact. The impact put dust and water into the atmosphere, witch changed the climate.
Many organisms did not make it through the extinction events. The groups were different for both extinctions. The Permo-Triassic event saw the end of the tabulate and rugose corals, and many species of crinoids and ammonoids. The Cretaceous-Tertiary event saw the end of the Dinosaurs, and all of the rest of the ammonoids.
Even though the two events were caused by different things, the result was the same, the Earth was changed forever.
1. Is the essay easy to understand (i.e. well organized and flows well)?
2. Did the author write an essay and not just a list of facts?
3. Does the essay include information about both the Permo-Triassic and the Cretaceous-Tertiary mass extinctions?
4. Does the essay correctly describe the magnitude of the Permo-Triassic mass extinction as more severe than the Cretaceous-Tertiary mass extinction?
5. Did the author include correct information about the cause(s) of the Permo-Triassic mass extinction?
6. Did the author include correct information about the cause(s) of the Cretaceous-Tertiary mass extinction?
7. Did the author include information about the groups of organisms that perished during the Permo-Triassic mass extinction?
8. Did the author include information about the groups of organisms that perished during the Cretaceous-Tertiary mass extinction?
9. Was material original and not just "Cut and Pasted" from the source material?
10. Are there spelling and grammatical errors?
11. How would you rate this text?
Mid Quality Calibration
Mass extinctions are events that kill-off many different groups of organisms on both land and in the sea at approximately the same time. They are caused by a variety of reasons. Two of the largest events were the Permian and the Cretaceous mass extinctions.
The Permian mass extinction was by far the largest in history. It was caused by climate change after the break-up of Pangea. The crustacious event was second largest. It was caused by a tidal wave in Texas and huge volcanoes around earth.
Most things on earth died in the Permian extinction. In fact, so much stuff died that there was space on earth for the dinosaurs. The dinosaurs died in the Cretaceous extinction.
There will probably be more mass extinctions in the future. We need to watch out for asteroids and other space objects.
Low Quality Calibration
Mass extinctions are common throughout earth history. They are events where many organisms die at one time. There have been 8 mass extinctions in earth history. Scientists identify mass extinctions by looking at the fossil record. The 2 most severe mass extinctions were the terminal Permian and the terminal Cretaceous. One had the dinosaurs die along with the pterosaurs, belemnoids, many species of plants (except amongst the ferns and seed-producing plants), ammonoids, marine reptiles, and rudist bivalves, and the other had the fusulinid foraminifera, trilobites,rugose and tabulate corals, blastoids, acanthodians, placoderms, and pelycosaurs, which did not survive beyond the Permian boundary. They were both caused by climate change and asteroids hitting the earth.