LaneTechCollegePrepHigh SchoolKrakowski 1

LECTURE 3: Paleozoic Era: Cambrian/Ordovician Periods

(543mya-245 mya)

  • What Life existed in the Early Cambrian Period (543 mya)?
  • Late Precambrian Period
  • Ediacaran Fauna
  • Limited Diversity
  • Early Cambrian Period (543-530 mya)
  • The “small, shelly fauna”
  • First Appearance of skeletalized parts: tiny plates, cones, and tubes, made of various minerals
  • Plant life is essentially limited to ______
  • TIMELINE OF CAMBRIAN EVENTS
  • 530 mya – Cambrian Explosion
  • 8 animal phyla
  • Porifera (sponges)
  • Cnidaria (jellyfish, corals)
  • Platyhelminthes (flatworms)
  • Arthropods (Trilobites)
  • Mollusks (bivalves/gastropods/nautiloids)
  • Echinoderms (Sea Stars)
  • Annelids (worms, leeches)
  • Chordates (spinal tube/Graptolites?)
  • 500 mya – First Vertebrate
  • First Jawless fish: Myllokunmingia
  • By the end of the Cambrian:
  • Trilobites DOMINATE
  • What was the Cambrian Explosion?
  • most animals appear in a relatively ______time in history (~530-520 mya)
  • great diversity of ______
  • All 8 animal phyla first appear in the fossil record: ______flourished
  • all of the eight major animals body plans in existence today, along with 27 minor ones, had emerged and no new body plans have developed since
  • What Trace Fossil marks the Beginning of the Cambrian Period?
  • Trichophycus pedum
  • Burrowing animal
  • No ______
  • What was the Burgess Shale?
  • Rocky Mountains of British Columbia
  • Discovered in 1899
  • It is ______million years old
  • Celebrated for its preservation of ______
  • Showed that ______Dominated!!
  • Why did the Cambrian Explosion Occur?
  • Increased ______in the atmosphere
  • At low ______levels, only simple metabolic tasks can occur
  • At high ______levels, more energy can be exerted to other tasks
  • Skeletonization
  • Low 02 levels, only small, ______forms
  • Allows larger body size- ______relationship
  • Predator-Prey Arms Races
  • First Predators arose during Cambrian (______)
  • This led to selection of diverse ______adaptations
  • ______prey
  • Shells in guts of large predators
  • What was the First Vertebrate?
  • First Jawless fish (______): Myllokunmingia 500 mya
  • Ancestor to Living Jawless Fish (______)
  • What Significant Event Happened at the end of Ordovician Period(500 mya- 439mya)?
  • ______#1 (439 mya)
  • At least ______of all species were wiped out.
  • Many species of trilobites, brachiopods, echinoderms, graptolites, and corals became ______
  • Why did this Mass Extinction Occur?
  • Global ______
  • Gondwana moved over the South Pole, causing glaciers to form and global temperatures to ______
  • Many species could ______cooler conditions
  • Suffered from ______as water turned to ice, lowering sea levels worldwide.