Silurian
Length of the period (era) 443 Million to 416 million years ago. Third period in the Paleozoic Era After the Ordovician Period Just before the Devonian Period (Bagley, 2014), (Markes, 2015)Bagley, 2014Markes, 2015
Extinction The Ordovician-Silurian mass extinction 1.Third largest extinction in Earth’s History million years ago. 2.Began in the Ordovician and ended in the Silurian with two peak dying times. 3.Most life was found in the sea a.Sea Creatures such as trilobites, brachiopods and graptolites significantly reduced in number. b.About 85% of sea life was wiped out 4.Cause of the extinction event thought to be an ice age. a.Triggered climate change and a fall in sea level leading to chemical changes of the water’s composition. (BBC, 2014)BBC, 2014
climate The climate changed greatly At the beginning the Earth was cool and covered in great ice sheets in the high latitudes Half way through the period the climate warmed Greenhouse effect Ice sheets melt Sea level rise High latitudes kept their glaciers and a cool climate Lower latitudes formed a warmer climate (Smithsonian)Smithsonian
what animals were present? In the Oceans: Stromatoporoids: corals and prehistoric sponges Eurypterids: sea scorpions largest arthropods ever lived (~2m long) Acanthodians: spiny sharks apex predator Benthic invertebrates Pentamerid community dominated by brachiopod (lamp shell) Reef mounds housed brachiopods, gastropods, crinoids, and trilobites Variety of jawless (Agnatha) and primitive jawed fishes Romundina (Placoderm) was first fish with developed jaws On land: Arthropods primitive centipedes and arachnids (National Geographic), )(Markes, 2015)National GeographicMarkes, 2015
CHANGES IN FAUNA ●Coral reefs made their first appearance ●Evolution of fishes ○rapid spread of jawless fish and the appearance of freshwater fish and jawed fish. ○the development of jawed fish allowed for an increase in carnivorous fish First evidence of life on land ascomycete fossils (fungi) arachnids and centipedes have been found. (Fischer et. al, 1998)Fischer et. al, 1998
plants on land Evolution of vascular plants There is debate about their formation during this period Baragwanathia fossil found in Australia Most of the first fossils were part of the genus Cooksonia This genus is characterized by branched plants with no leaves and sporangia on the tips of the branches The development of vascular plants formed the basis for most modern plants today (Markes, 2015)Markes, 2015
Bibliography Bagley, Mary. "Silurian Period Facts: Climate, Animals & Plants." LiveScience. TechMedia Network, 19 Feb Web. 28 Jan Used for the information of the length of time of the era. Fischer, Dan, Tammy Liu, Emily Yip, and Korsen Yu. "The Silurian Period." University of California Museum of Paleontology. University of California Museum of Paleontology, 11 May Web. 28 Jan Used for the information regarding the changes of fauna. "Silurian Period." National Geographic. National Geographic Society, Web. 28 Jan Used for the information regarding the animals present during the era. Johnson, Markes.. "The Silurian Period." Encyclopaedia britannica, 6 March Web. 29 Jan Used for information on the period duration and animals present. Used for images "Silurian : Geology and Climate." Silurian : Geology and Climate. Smithsonian Institution National Museum of Natural History, n.d. Web. 31 Jan Used for climate information "Ordovician-Silurian mass extinction" BBC, Oct Web. 29 Jan Used for extinction information and image on extinction slide