Geos dino notes - Dino notes The worst thing about the object that struck earth 65 Ma was a its toxic composition b the site of the impact c its

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Dino notes January 17, 2008 The worst thing about the object that struck earth 65 Ma was: a) its toxic composition b) the site of the impact c) its velocity (correct answer) d) the eruption it caused e) all of the above Lines of Arrested Growth (LAGs) = show age of a dinosaur • Found in Bones • Similar to tree rings
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Dino notes Gigantoraptor • 26’ long, 11’ at hips, 3000 lbs. • Related to Oviraptor, only BIGGER • LAGs show age - Gigntoraptor grew extremely fast, died at age 11 • Lived 80 Ma • Warm or Cold blooded Stratigraphy • Study of rock layers • Reconstruct ancient environments and the evolution of ancient landscapes • Correlate rocks of same are that are widely separated geographically • Biostratigraphy, magnetostratigraphy, carbon isotope stratigraphy, absolte dating by radio isotopes. Principle of faunal succession • “fossil species succeed each other in a definite and recognizable order” • Sedimentary rocks represent time: lower = older, upper = newer (Law of Superposition) • Distinctive fossils or assemblages of fossils can be used to correlate widely separated rocks as being the same age. Shelly maine fossils and microfossils, and pollen are usually best. Lingo • Species: a population of organisms that can interbreed to produce fertile offspring. • Genus: a collection of one or more species (pl. Genera) • Gradualism, uniformitarianism: biological and geological changes happen very slowly through time. 5 major mss extinctions (three of interest): • Permo-triasic, 250 Ma - made way for ancestors of dinos. • End-Triasic, about 200 Ma - took out last of large archosaur competition to the dinos • K-T, 65 Ma, took out dinos Proposed causes of dino extinction • out-competed by smarter, egg-eating mammals • disease • falling sea level • volcanically driven climate change • astroid strike January 29, 2008 Platypus • Lay eggs, 40,000 glands in bill that sense electrical currents • 112 Ma platypus jaw found with large nerve canal to glands • kinds of mammals: placental, marsupial, monotreme • new fossil almost doubles the age of the oldest known monotreme • would you expect the oldest monotreme fossils be older that the oldest placentals
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Dino notes According to Terri, warm bloodedness evolved n out lineage: a) 280-250 Ma (correct answer) b) 250-200 Ma c) 200-100 Ma d) We don’t know Why pits in the muzzle indicated whiskers: • pits indicated whiskers • whiskers indicated fur • fur indicated warm-bloodedness Why is extinction important? Extinction provides for the evolution of other animals. Warm-bloodedness in Great White Sharks tells us: Warm bloodedness has evolved independently more than once. Evidence for K-T impact
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This note was uploaded on 04/02/2008 for the course GEOS 216 taught by Professor Richardthompson during the Spring '08 term at University of Arizona- Tucson.

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Geos dino notes - Dino notes The worst thing about the object that struck earth 65 Ma was a its toxic composition b the site of the impact c its

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