Science notes Question: What happened in the 5 mass extinctions and how did the extinctions happen? Ordovician-Silurian mass extinction Third largest mass extinction Most life was in the sea 86% of sea life went extinct Trilobites died Brachiopods died Graptolites died An ice age was blamed for this mass extinction They think climate change was the cause for this Fall in sea level Messed up the chemistry of the oceans 443 Mya End of Ordovician period Start of Silurian period Late Devonian mass
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Geology.com. Retrieved December 9‚ 2012‚ from http://geology.com/rocks/limestone.shtml 4. Viruete‚ E. J. (2010). Geochemical characteristics of the Río Verde Complex‚ Central Hispaniola: Implications for the paleotectonic reconstruction of the Lower Cretaceous Caribbean island-arc. Lithos‚ 114(1-2)‚ 168-185. Retrieved December 10‚ 2012‚ from http://www.sciencedirect.com
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Transitions of Reptiles to Mammals A long long time ago‚ in a galaxy not too far away‚ was a little blue planet called Earth‚ and on this world not a single mammal lived. However a lot of time has past since then and we now have lots of furry creatures that are collectively called mammals. How did they get their? Where did they come from? These are the kinds of questions that led me to my subject of choice. I will endeavor to provide examples‚ using specific transitional fossils‚ to show that
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The Origin of Birds For as long as cohesive evolutionary theories have been in place‚ the heated debate regarding the origin of birds and their relationship to dinosaurs has raged on. After the 1860s birds have been hypothesized as being closely related to an ample assortment of extant and extinct reptile lineages. These include a diversity of basal archosaurs and archosauromorphs‚ pterosaurs‚ crocodylomorphs (including modern crocodylians and their Mesozoic relatives)‚ and various theropod ornithischian
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today‚ about 99.9 percent of all species that have existed on Earth are extinct. These five extinctions were the Ordovician-Silurian extinction‚ the Late Devonian extinction‚ the Permian-Triassic extinction‚ the End Triassic extinction‚ and the Cretaceous-Tertiary extinction. They wreaked havoc on more species than you could imagine‚ and if you think today that there are a lot of species‚ imagine if the five mass extinctions hadn’t happened. The Ordovician-Silurian extinction occured about 459
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The Alps are the youngest and highest mountain system in Europe. They stretch across the western and southern part of the continent in a broad arc. The mountain range startsnear the Mediterranean Seaon the border between France and Italy. Then it curves north- and eastward through northern Italy‚ Switzerland Liechtenstein‚ southern Germany‚ Austria and Slovenia. The Alps are about 1‚000 km long‚ the broadest section over 260 km wide. The highest peak‚ Mont Blanc‚ situated on the border between
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Evolution of the Earth The planet earth has gone through much abuse and punishment in the past. Formed approximately 4.5 billion years ago‚ the earth has undergone multiple catastrophic asteroids erasing species after species. Due to geologic evidence‚ it is estimated over 90 percent of all life that had ever lived in this planet have been extinct. No more than the past 500 million years alone‚ 50-90 percent of all organisms on earth were wiped out of the geological timeline without any warning
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Insert Name: Instructor’s Name: Course: Date: 08/July/2010 Sharks have been in existence for more than 300 million years. Their evolution occurred over 150 million years earlier than that of the dinosaurs. Most of the existing fossil data of early sharks was collected from fossilized teeth together with several skin impressions. primitive sharks (Cladodonts) ‚ had teeth which were double-pointed‚ up to 2metres in length‚ ate fish as well as crustaceans‚ and existed approximately
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Before that time‚ at least some hermit crabs used ammonites’ shells instead‚ as shown by a specimen of Palaeopagurus vandenengeli from the Speeton Clay‚ Yorkshire‚ UK from the Lower Cretaceous.[14] [edit] As pets Photo of four hermit crabs. Four hermit crabs in an aquarium Several marine species of hermit crabs are common in the marine aquarium trade. Of the approximately 15 terrestrial species in the world‚ the following are commonly
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Biology Unit 4 Chapter 1: “Terrible Lizards” Paleontologist: someone who studies “ancient organisms” Paleobiology – the study of ancient life Paleontology is particularly important with regard to scientific theory‚ since for many children dinosaurs are the first exposure to scientific concepts Early Dino Stuff In 1676- large meat- eating femur (Megalosaurus) was discovered and people thought it was a giant human’s scrotum – “Scrotum humanum” First scientific name given to dinosaur Prior to 1800s
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