BIOL 3P03 Lecture Notes - Lecture 1: Trilobite, Aragonite, Chalcis
9 Jan 2017
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Document Summary
Being a paleontologist is like being a coroner except that all the witnesses are dead and all the evidence has been left out in the rain for 65 million years. Mesozoic & cenozoic-to be identified based on their fossil content (boundaries marked by mass extinctions) Fossils were not universally accepted to be the remains of organisms until the renaissance/ age of reason. In the 17thc stenorecognised that the teeth in a dead shark closely resembled glossopetrae (tongue-stones), and he hypothesised that sediments lithified around remains that fossilised. the first. Even today, living relatives are important-it is hard to imagine how the cephalopod affinities of ammonites could have been inferred prior to 1829, when living chambered nautiluswas discovered. The fossil record is strongly skewed toward organisms with mineralised hard parts, like the calcareous brachiopods and bryozoans that make up the bioclasticlimestones below. Nonetheless, fossils are not uncommon in phanerozoic sediments/ sedimentary rocks, particularly those deposited in shallow marine and lacustrine environments.
