Evolutionary Fauna and Taphonomy (a) - Lecture 4 Flashcards
What is it called when the origination rate exceeds that of extinction?
Radiation
Name the three evolutionary faunas and typical examples of each
Cambrian (inarticulate calcareous brachipods, hyothilids) Palaeozoic (graptolites, corals) and Modern (mammals, reptiles)
What was significant about the palaeozoic evolutionary fauna?
Rise of more specialised ‘stenotopic’ (Can only occupy a restricted range of habitiats) organisms
What is taphonomy the study of?
The conditions and processes by which organisms become fossilised
What does biostratinomy the study of?
The processes that take place once an organism dies but before its final burial
What does diagenesis mean?
Changes to sediment during and after lithification
What are the three main agents of taphonomy?
Biological (bacterial decomposition), Physical (disintegration, transportation, abrasion) and Chemical (dissolution/recrystallisation of mineralised hard parts
What are more likely to be fossilised? a) mineralised infaunal marine organism b) soft-bodied epifaunal terrestrial organism?
Answer: a)
What is meant by a ‘community’ of organisms?
A recurrent assemblage of organisms
inhabiting a specified space linked to the
environment, e.g. a group of organisms living and interacting in the
same habitat
What is at the base of a trophic pyramid?
Primary Producers
Define the term ‘trophic nucleus’
Dominant species forming >80% of fauna
