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Paleozoic Era Invertebrates. Chapter 12 Part 2. Cambrian. Cambrian explosion Burgess Shale Trilobites, brachiopods, archaeocyathids Sauk Sea regression. Ordovician. Tippecanoe sequence Warm climate New environments. Ordovician sea floor. New diversity of fauna with shells.
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Paleozoic Era Invertebrates Chapter 12 Part 2
Cambrian • Cambrian explosion • Burgess Shale • Trilobites, brachiopods, archaeocyathids • Sauk Sea regression
Ordovician • Tippecanoe sequence • Warm climate • New environments
Ordovician sea floor • New diversity of fauna with shells
Ordovician Acritarchs • Phytoplankton
Ordovician reef builders • Bryozoan • Colonial, benthonic, sessile suspension feeders
Ordovician reef builders • Bryozoan • Colonial, benthonic, sessile, suspension feeders
New Ordovician animals • Brachiopod with hinged shells • Articulate brachiopod • Benthonic suspension feeder
Ordovician • Class: cephalopod • Subclass: nautiloid • Simple sutures between chambers
Ordovician class: cephalopod • Subclass: nautiloid • Simple sutures between chamber
Ordovician class: cephalopod • Simple sutures • Straight & curved shell • Up to 30 feet long • Major predator
Ordovician class: cephalopod • With rise of cephalopods, trilobites decline • Remaining species w/ specialized protection
Ordovician mass extinction • 60% of marine invertebrates extinct • Reefs decimated • 2nd worst extinction • 100 families ended
Ordovician mass extinction • Victims were tropical • Replacements: deep and cold water adapted • Cause?
Post-extinction • Recovery and diversification • Brachs., bryozoans, corals recover in Silurian
Silurian and Devonian • Reefs doing well • Lots of corals
Silurian & Devonian • Eurypterids abundant • “Sea scorpions” • Top predator
Other Silurian eventsColymbosathon ecplecticos • Oldest penis in the fossil record
Other Silurian events • Oldest insect found by jaw • Jaw found only on flying insects • Insects some of first animals on land?
Devonian • Class: cephalopod • Subclass: ammonoids • Related to nautiloids • Nautiloids: simple sutures • Ammonoids: complex sutures
Devonian • Class: cephalopod • Subclass: ammonoids • Related to nautiloids • Nautiloids: simple sutures • Ammonoids: complex sutures
Carboniferous • Reefs dominated by crinoids
Crinoids • “sea lilies” • Related to sea starts and sea urchins • Benthonic, suspension feeders • Meters long • Carboniferous limestone full of these
Crinoids • “sea lilies” • Related to sea starts and sea urchins • Benthonic, suspension feeders • Meters long • Carboniferous limestone full of these
Paleozoic critters • Reef builders • Bryozoans • Corals • Brachiopods • inarticulate • articulate • Cepahlopods • nautiloids • ammonoids • Crinoids
Permian extinction • Greatest mass extinction • Gone: • 50% of marine invertebrate families • 90% of marine invertebrate species • 65% amphibians/ reptiles • 33% insects
Permian extinction • Greatest mass extinction • Gone: • 50% of marine invertebrate families • 90% of marine invertebrate species • 65% amphibians/ reptiles • 33% insects
Permian extinction • Global cooling? • Evidence of warming at end of Permian • Change in ocean chemistry? • Land animals affected too
Permian extinction • Meteorite impact? • Impact site in Australia • Big enough to cause largest extinction?
Permian extinction • Loss of habitable shallow marine areas? • Pangaea mostly formed before extinction
Permian extinction • Increase in CO2 levels • Lead to global warming • Major anoxic event • How to raise CO2 levels? • Massive volcanic eruptions in Siberia • Release of methane from sea floor • Sea level drops, organic matter oxidizes (rots) and rotting sucks up oxygen