Palaeontology Flashcards
What is a body fossil
fossilised parts of an actual organism
- mostly hard parts, biomineralised
- exceptional preservation includes soft parts
- life or death assemblages
What is a trace fossil
Evidence of past behaviour of organisms
- footprints, tracks, burrows
- always life position - good environmental indicator
What is a chemical fossil
Relics of biogenic chemical compounds / geochemical signatures of organisms found in rocks
- stable chemical compounds formed from degradation of biological c.c.s
Ranks in linnaean taxonomic system
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
What are the 3 domains of life
Archea
Bacteria
Eukarya
What is taphonomy
process of fossilisation (biostratinomy + diagenesis)
What is biostratinomy
Processes that occur between death and burial of an organism
(decay, transport, deformation, destruction)
What is diagenesis (paleo)
processes that occur between burial and discovery of a fossil
(recrystallisation, dissolution, deformation)
What are the ways that information can be lost during fossilisation
Decay - Aerobic rapid decay soft tissue (timing important)
Transport - far=lost environmental indicator (identify by way up, abrasion, fragmentation)
Destruction - common to species with hard parts held together by soft parts, bio erosion, dissolution(carbonate)
Deformation - distort under pressure, not represent life morphology
What questions to ask in identifying preservation
- is original material? (ammonite MOP)
- has been replaced? (pyrite, phosphate, silica)
- covered/infilled (cast/mould)
When are soft parts preserved
when rate of burial/fossilisation beats rate of decay
3 ways soft parts can be preserved
Ephemeral preservation - env factors prevent decay (low temp)
Early mineralisation - replicates morphology of soft parts
Organic preservation - some biopolymers more resistant to decay (eg feathers)
Periods in Paleozoic
Cambrian
Ordovician
Silurian
Devonian
Carboniferous
Permian
Periods in Mesozoic
Triassic
Jurassic
Cretaceous
Periods in Cenozoic
Paleogene
Neogene
Quaternary