Please enable JavaScript.

Coggle requires JavaScript to display documents.

Main Body Plans (4) Graptolites (Good index fossil (common, globally…

- - - - very common Cambrian
      - extinct few Myr later
- - - - some rigid & hard
        since silica-rich
      - some soft
  - - - snowflake-like silica bits comprising skeleton
- - - - hard features fossilise easily
    - - shell bits worn & mixed by currents
      - indicates past local conditions (currents types, transport)
- - - - rarely whole thing
      - individual ossicles - circular/star plates
- - - - Microscopic --> Macroscopic
      - First predators
      - Skeletons develop
      - Major modern divisions established
        
        Trace fossils appear
      - Rapid diversification life
- - - - honeycomb texture where individual polyps inhabit chambers
    - - live in horn-like structures