Cambrian period

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  1. What first occurred during the Cambrian period?
    mobility, sexual reproduction, early skeleton (but still mostly soft bodies), all major animal phyla in existence today, bilaterians, and likely sponges and Cnidarian
  2. Major faunal turnover occurred
    before and after the Mesozoic era (after Paleozoic era and before Cenozoic era)
  3. Which clades formed monophyletic groups early in animal evolution?
    protostomes and deuterostomes
  4. The Cambrian "explosion" refers to
    the major overall diversification of animals (Metazoans) over a relatively short period of time; increase in taxonomic diversity (# of types of animals), skeletonization, trace fossil diversity, and body size
  5. Which phyla make up the clade of protostomes?
    Arthropoda, Brachiopoda, Mollusca, Annelida
  6. During gastrulation, the mouth forms first.
  7. Which phyla make up the clade of deuterostomes?
    Echinodermata, Hemichordata, Chordates
  8. During gastrulation, the anus forms first.
  9. Phylum Arthropoda consist of
    trilobites, chelicerate, crustaceans, and hexapods
  10. Phylum Brachiopoda were highly diverse in the __ era.
  11. There was a heavy loss of Phylum Brachiopoda at the end of the __ period.
  12. Lophophorates refer to Phylum __
  13. Clams are morphologically similar to Phylum __ but belong in Phylum __
    Brachiopoda (bi-valved); Mollusca
  14. Phylum __ are extremely diverse protostomes
  15. Phylum Mollusca consist of
    Gastropoda (snails), Bivalvia (clams, oysters), Amminoidea (ammonites), Cephalopoda (squid & octopods)
  16. Phylum __ have bilateral and pentameral symmetry
  17. Which phylum is most closely related to Chordata?
    Echinodermata (both Deuterostomes)
  18. Phylum Echinodermata consist of
    Crinodiodea (sea lillies): abundant in Paleozoic, Echinoidea (urchins), Asteroideia (starfish), and Holothuraians (sea cucumbers)
  19. The most diverse deuterostomes are Phylum __
  20. The 3 subphyla of Phylum Chordata are __
    Urochordata, (Tunicates/Sea Squirts), Cephalochordata (Amphioxus), Vertebrata
  21. The one phyla that appears after the Cambrian period are __
    Phyla Bryozoans (Most likely they were around the Cambrian, but not preserved until the Oridovician period)
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Cambrian period
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