Fossils are the remains or traces of ane time living organisms. Our introduction to paleontology (the report of fossils), volition live express to those forms that are usually preserved in addition to geologically useful. For Historical Geology purposes, nosotros volition live concerned amongst ii aspects of paleontology: (1) fossils every bit indicators of relative historic menses (using the Principle of Floral in addition to Faunal Succession. fossils every bit indicators of environment. All organisms are subject on their environments for survival. Some organisms, however, tin live on exclusively inwards restricted environments. Consequently, nosotros tin apply the regulation of uniformitarianism to fossils to translate the surround inwards which they lived. Modern fish, for example, tend to alive inwards water. Ancient fish, then, likely lived inwards H2O every bit well. We volition dissever the environments into ii basic categories– the terrestrial (land-based) environment, in addition to the marine (ocean) environment. Because marine fossils are almost usually preserved, the marine environments are shown inwards figure1.
Shallow marine bottom-dwelling organisms such every bit corals stand upwards for the benthic environment. Similarly, approximately species of fish request the neritic surround (the shallow seas roofing the continental shelves). Other organisms such every bit radiolarians in addition to approximately diatoms are feature of the oceanic or deep bounding main environment. Still other organisms inhabit the bounding main inwards both the neritic in addition to oceanic areas in addition to only advise a pelagic environment.
Marine fossils tin live farther described inwards damage of their life habits. These habits are shown inwards Figure A2. Corals, for instance tend to live attached to the bottom in addition to are hence referred to every bit benthic (bottom dwelling) sessile (fixed). Lobsters, however, movement along the bounding main bottom in addition to although soundless benthic, are besides considered vagrant. Swimming in addition to floating organisms are referred to every bit nektonic in addition to planktonic, respectively. In our instance above, approximately fish powerfulness stand upwards for the nektonic pelagic environment.