term1 Definition1term2 Definition2term3 Definition3
Please sign in to your Google account to access your documents:
Sepkoski
Divided all Phanerozoic marine animals into three overlapping Evolutionary Faunas, of which all three date back to the Cambrian explosion and extend to present day
Cambrian Fauna
-Trilobites, archaic molluscs, archaic echinoderms and inarticulate brachiopods
-mainly mudgrubbers
-dominate the Cambrian, reduced in Ordovician, insignificant since then
Paleozoic Fauna
-reflects advent of armoured filter-feeders and pelagic predators during the Ordovician Radiation
-bryozoans, brachiopods, corals, crinoids reflect ecological tiering of suspension feeders (low mobility, heavily armoured)
- cephalopods new top carnivore ("ambush" pelagic predator)
- dominate Paleozoic, but diversity was reduced by 75% by the Permian extinction event and never recovered
Modern Fauna
-gastropods, bivalves, crustaceans, echinoids, bony fish
-less armoured and more mobile than other fauna, due to predation (speed and weapons) and biological bulldozing (burrowing deeper, causing less stable sediment for filter feeders)
Hierarchy of Mass Extinctions
Major: Permian (>50% family extinction)
Intermediate: Ordovician, Devonian, Triassic, Cretaceous (10-50%)
Lesser: others (3-10%)
Biogeographic Provinces
Areas with distinct biotas, reflecting geography and climate
Maximize diversity during periods of strong climatic gradient and maximum continental seperation
Simpson Similarity Index
Measures degree of similarity between two biogeographic provinces
Epeiric Seas
Shallow seas which covered almost all of North America during Ordovician
Tidal Environments
- supratidal and intertidal flats
- high salinity, periodic exposure and drying in hot arid environment
- abundant cyanobacterial stromatolites, some ostracods and trilobites capable of withstanding extremes
Tetradium Thicket
-analogous to modern fringing reef attached to shoreline
-coral rubble attracted scavengers (gastropods and trilobites). colonized by filter-feeders (bryozoans), microniches for dwellers (brachiopods and bivalves)
Need help typing ? See our FAQ (opens in new window)
Please sign in to create this set. We'll bring you back here when you are done.
Discard Changes Sign in
Please sign in to add to folders.
Sign in
Don't have an account? Sign Up »
You have created 2 folders. Please upgrade to Cram Premium to create hundreds of folders!