Lecture 4: fossilization Flashcards
biostratinomy
everything that happens to an organism between death and burial, most parts of an organism won’t survive biostratinomy process
- Damage before burial includes
- disarticulation from predators and scavengers
- Boring from insects
-Decomposition from microbes
- Weathering from wind and rain
- What remains: mineralized bones, teeth, shells (skeletons)
body fossil
the physical remains of an organism, rare to find whole intact skeletons, typically fragmented and damaged
- usually reconstructors take what is found and reconstruct the whole skeleton
trace fossil
ichnofossil, remains of an organism but not the organism itself (trackways, poop, bite marks) that show its behavior
molecular fossil
ancient DNA, proteins, lipids
- lasts 10-20M years
- cells like pigments of skin can also get preserved (but only a shadow of it)
diagenesis
everything that happens to an organism between burial and discovery
- loss of any remaining organic matter, most decayed away in fossilization process but collagen is tough and can survive
- lichen and other fungi can contaminate bones and produce collagen
- some dinosaur bones have unique bacterial communities living inside them
fossil
the preserved remains of a prehistoric organism (in geologic rock record)
hydroxyapatite
the main mineral in bones; reacts with other minerals in the earth especially if there is water → can lead to dissolution of original material and replacement by inorganic materials
- the older the fossil, the more likely it is to be replaced
- enamel of teeth have even higher mineral concentration => easier to preserve
lagerstatte
a fossil deposit with exceptional preservation; anoxic environments that preserve many individuals with evidence of soft tissue
bone bed
hundreds or thousands of bones preserved in one site of the same or multiple species
