Evolution and climate

• Geologic time scale refers to the chronological sequence of geological events over billions of years.
• Chambered Shell


  • Siphuncle to control buoyancy
• Cephalopods have a chambered shell with a siphuncle to control buoyancy
• Nautiloids have a smooth shelled chambered shell
• Goniatites are a type of cephalopod
• Ceratites have mostly smooth shelled chambered shells, with some increment
• Ammonites have a variety of ornament on their chambered shells
• Burgess Shale


  A geological formation in Canada, known for exceptional preservation of Cambrian period fossils, including soft-bodied organisms.
• Cambrian period


  A time of rapid evolutionary diversification, occurring 541-485 million years ago.
• Soft-bodied organisms


  Fossils of animals without shells or skeletons, often preserved in the Burgess Shale, that were previously unknown to science.
• Benthonic: Organism lives on or in the sediment substrate of the sea floor
• Pelagic: Organism living freely suspended in water column
• Planktonic: Pelagic organism unable to swim against currents, carried passively by ocean currents
• Sessile: (of an organism, e.g. a barnacle) fixed in one place; immobile
• Index Fossil: A fossil species used as a marker to define a biozone
• Vagrant: Organism that moves around on the sea floor
• Infaunal: Organism that lives in the sediment
• Epifaunal: lives on the sediment
• Nektonic: actively swims in the water column