EARLY PALEOZOIC LIFE

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EARLY PALEOZOIC LIFE
The Cambrian Explosion
Cambrian Explosion Evolutions big
bang lasted about 10 million years All
principal animal phyla except Bryozoa appeared
between 535 to 520 myBP
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EARLY PALEOZOIC LIFE
Continuing Diversification
By the Ordovician, global biodiversity
tripled Included trilobites, brachiopods,
bivalve molluscs, gastropods and coralline
animals Ordovician mountain building may have
created new habitats The number of infaunal
organisms increased
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EARLY PALEOZOIC LIFE
Unicellular Organisms (Protistans)
Foraminifera First appeared in the
Cambrian Survive to present
Platysolenites, a Cambrian foram Agglutinated
form Calcareous skeleton
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EARLY PALEOZOIC LIFE
Unicellular Organisms (Protistans)
Radiolaria First appeared in the Cambrian, more
abundant in mid-Paleozoic Survive to
present Have a siliceous skeleton
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Archeocyathids (ancient cup) Early Cambrian
phylum Have similarities to both corals and
sponges Associated with stromatolites
Reef-builders of Early to Middle Cambrian 60 m
thick, 200 km long Extinct at end of Cambrian
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Archeocyathids (ancient cup)
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Phylum Porifera (sponges) Early Cambrian
phylum Evolved from colonial flagellated,
unicellular organisms Conservative evolutionary
history All but one modern class of sponges
were present in Cambrian Exist to present
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Phylum Porifera (sponges)
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Phylum Porifera (sponges) SPICULES
Spicules Composed of Calcium carbonate
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Phylum Porifera (sponges) SPICULES
Spicules Composed of Silica
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Phylum Porifera (sponges) SPICULES
Spicules Composed of Spongin
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Phylum Porifera (sponges) Cambrian
Protospongia
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Phylum Porifera (sponges) Ordovician
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Phylum Porifera (sponges) Silurian
Caryospongia
Astylospongia
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Phylum Porifera (sponges) Silurian
Palaeomanon
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Phylum Porifera (sponges) Silurian
Astraeospongia Star-shaped spicules
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Stromatoporoids Calcareous sponges Geologic
range Ordovician to Present Built reefs in
the Silurian (Michigan Basin) Found in
Caribbean Sea, Mediterranean Sea and Pacific
Ocean
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Stromatoporoids Side view
Laminae and Pillar Structure
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Stromatoporoids Top view
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Cnidaria (Coelenterata or Corals) Includes
Sea fans Jellyfish Anemones Corals Very
diverse group Stinging cells cnidocytes Radially
symmetrical
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Cnidaria (Coelenterata or Corals)
Fire coral
Jellyfish
Sea fans, gorgonian
Modern corals
Horn corals
Tabulate corals
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Cnidaria (Coelenterata or Corals)
Two forms Polyps and Medusa Polyps
asexual Medusa - sexual
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Cnidaria (Coelenterata or Corals) Stinging
cells Cnidocytes
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Cnidaria (Coelenterata or Corals) Stinging cells
or Cnidocytes
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Rugosa (Rugose or Horn Corals) Ranged from
Ordovician to Permian Not major reef formers,
colonizers Usually solitary Abundant in
Silurian and Devonian reefs
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Rugosa (Rugose or Horn Corals)
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Rugosa (Rugose or Horn Corals)
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EARLY PALEOZOIC LIFE
Metazoan Invertebrates
Rugose growth