THE FOSSIL RECORD

TYPES
Fossilisation process
How good is it?
Bias
Rock Strata
Whole Organism
Trace fossils
Microfossils
Resinfossils
Pseudofossils
Living fossils
e.g. bodies that are mummified in a very dry & cold climates
enormously well preserved
have a lot of taxonomic characters
e.g. Carnivorous Dinosaur Coprollite (poop)
e.g. Laetoli Hominid footprints 3.5Mya
imprint
plant /animal fossil
Fossil within a fossil
inorganic objects, markings, or impressions that might be mistaken for fossils
Rock fissures are filled up with percolating minerals (geologic rather than biological process)
e.g. manganese dendrites, moss agate
formed in shallow water by the trapping, binding and cementation of sedimentary grains by biofilms of microorganisms, especially blue‐green algae
Major constituent of the fossil record for the first 3.5 billion yrs
e.g. Stromatolites, Shark Bay
e.g. Coelacanth - Latimeria chalumnae (fish)
e.g. Gingko Biloba (plant)
Formation types
dependent on:
ultimately - need to form ROCK
Compression, casts & moulds, permineralisation, unaltered remains
• Durability (hard vs soft) • Burial (saturated sediment) • Lack of oxygen
± 250 000 described fossils (not a lot)
Lineages are separated by long periods of time
Gaps of many thousand years
Fossil species are only known from a few specimens
Geographic (sampler and habitat)
Taxonomic
Temporal
Rocks arranged in a predictable pattern with strata found in the same relative position
Assemblages of fossils from older to younger rocks
Layers of sediment contain distinctive suites of fossils
Radiometric dating provides a time sequence
Fossil record provides evidence of changes that have occurred in the history of life

	Created by chaz_id89 over 10 years ago

	Copied to Note by chaz_id89 over 10 years ago

undergraduate degree genetics and evolution Note on MACROEVO & FOSSIL RECORD - created from Mind Map, created by chaz_id89 on 05/11/2013.

MACROEVO & FOSSIL RECORD - created from Mind Map