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Precambrian Eukaryotes. Acritarchs Ediacaran Vendian. Cysts of unicellular eukaroytes, perhaps algae or egg cases of multicellular orgs. 1800 my through Devonian. Acritarchs. Ediacaran. 600 my-545 my Soft-bodied Many organisms of uncertain affinity.
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Precambrian Eukaryotes Acritarchs Ediacaran Vendian
Cysts of unicellular eukaroytes, perhaps algae or egg cases of multicellular orgs. 1800 my through Devonian Acritarchs
Ediacaran • 600 my-545 my • Soft-bodied • Many organisms of uncertain affinity
Possible mollusc? Probable cnidarian
Vendian • “little shellies” • Right at Cambrian boundary
Cambrian Trilobites: Extinct arthropods (like lobsters or shrimp but with calcite skeleton)
Burgess Shale • Middle Cambrian • Excellent preservation of soft-bodied orgs. • 5 kinds of arthropods (only 3 kinds today) • First vertebrate • Mysterious critters
Cambrian • Smallish • Skeletons (if any) of phosphate or thin CaCO3 • Live on or near ocean floor • Sponges, trilobites, early molluscs, echinoderms, lingulate brachiopods
Ordovician Brachiopods (articulate)
Ordovician invertebrates • More robust skeletons • Calcite skeletons • Taller, deeper (take up more ecological space) • The Paleozoic fauna appears: rhynchenelliform brachiopods, bryozoans, crinoids/blastoids, primitive cephalopods, graptolites, rugose/tabulate corals
Middle-Late Paleozoic • Increasing height, increasing depth • Increasing diversity • New organisms • Eurypterids (giant sea scorpions) • Fish/amphibians
Paleozoic What if… • You were running the Paleozoic Ultimate Fighter show, and you had to design matchups between different Paleozoic creatures. Organize at least two matchups between two different kinds of creatures off the list. Who would be good opponents to match up? In each case, who would win and why? • You were at a Paleozoic banquet and were offered these creatures to eat: • Brachiopod • Bryozoan • Crinoid • Trilobite Which one would you rather eat? Why?
Oceans - a whole new crew The Modern Fauna Mollusks Crustaceans Echinoids Fish Mesozoic Life
Bivalves Molluscs Gastropods
Oceans - a whole new crew The Modern Fauna Mollusks Crustaceans Echinoids Fish Plus marine reptiles and ammonites Mesozoic Life
Cenozoic Oceans • Like Mesozoic: Modern Fauna • Minus marine reptiles and ammonites • Plus whales and marine mammals
Evolution of Tetrapods • Arise from sarcopterygians (lobe-finned fish) • Amphibianish creatures • Reptiles (to birds) • Mammals
Adaptations for life on land • Breathe! • Locomotion • Avoid dessication • Reproduction - amniotic egg allows longer development (no swimming larvae) • Leathery covering or eggshell • Larger size of egg • Larger yolk
Adaptations for life on land: plants • Avoid dessication – thicker outsides • Reproduction – • Fancy fertilization methods, seeds • Marine plants release gametes into water • More complicated dispersal mechanisms for young
Reptiles • Anapsids: turtles and their ancestors • Synapsids: pre-mammals & mammals
Reptiles • Anapsids: turtles and their ancestors • Synapsids: pre-mammals & mammals • Diapsids: Rest of reptiles • Marine reptiles • Snakes, lizards • Pterosaurs • Crocodilians • Dinosaurs and birds