Directed reading Flashcards
1
Q
Bertazzo 2015
A
- Thought that proteins cant last more than 4 million years
- Quaternary structure of collagen fibres found in unexceptionally preserved bones
- 67nm banding typical of that found in collagen
- Previous to these 75million year old samples oldest non-degraded collagen found was 4million years old
- Red blood cells present have the potential to be used to help assess metabolic rates, and help ascertain when and how the transition from ectothermy to endotermy took place on the avain stem lineage
2
Q
Marshal 2021
A
- Abundance of T.rex at any one time was 20,000Persisted for 127,000 generations
- 2.5 billion lived
- Fossil recovery of 1 per 80 million Individuals or 1 in 16,000 were its fossils were more abundant
3
Q
Smith 2003
A
- Removing bias for where there is more exposed rock meaning higher specimen diversity through refraction (statistical technique using subsampling to reduce populations to the same size)
- Worked for north america on stable cratonic platform
- Didnt work for newzealand whose past 60million years have been on a tectonically active margin meaning distruction of lots of specimens
4
Q
Zhou 2003 (environment)
A
- Jehol group found in northeastern china
- Regional volcanism and presensce of numerous shallow lakes provides env for preservation and high resolution dating
5
Q
Zhou 2003 (Processes)
A
- Dead organisms entered lakes, burried rapidly and ecased in fine-grained sediments
- Most productive horizons are beneath ash tuff falls (entombed most organisms present in water column)
- Tuff layers correlate with mass mortality events
- Create anoxic microenvironemnt halting bacterial decay creating konservat-langerstannnen
6
Q
Zhou 2003 (specimens)
A
- Precursors of feathers= filamentous integumentary structures present on coelurosaur sinosauropteryx (basal coelurosaurian)
- Feathers had broader phylogenetic distribution within theropods, not unique to birds
- Feathers don’t correlate with the origin of flight
