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EARLY PALEOZOIC LIFE. The Cambrian Explosion. Cambrian Explosion Evolution’s “big bang” lasted about 10 million years All principal animal phyla except Bryozoa appeared between 535 to 520 myBP. EARLY PALEOZOIC LIFE. Continuing Diversification.
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EARLY PALEOZOIC LIFE The Cambrian Explosion Cambrian Explosion Evolution’s “big bang” lasted about 10 million years All principal animal phyla except Bryozoa appeared between 535 to 520 myBP
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
EARLY PALEOZOIC LIFE Unicellular Organisms (Protistans) Foraminifera First appeared in the Cambrian Survive to present Platysolenites, a Cambrian foram Agglutinated form Calcareous skeleton
EARLY PALEOZOIC LIFE Unicellular Organisms (Protistans) Radiolaria First appeared in the Cambrian, more abundant in mid-Paleozoic Survive to present Have a siliceous skeleton
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
EARLY PALEOZOIC LIFE Metazoan Invertebrates Archeocyathids (“ancient cup”)
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
EARLY PALEOZOIC LIFE Metazoan Invertebrates Phylum Porifera (sponges)
EARLY PALEOZOIC LIFE Metazoan Invertebrates Phylum Porifera (sponges) SPICULES Spicules – Composed of Calcium carbonate
EARLY PALEOZOIC LIFE Metazoan Invertebrates Phylum Porifera (sponges) SPICULES Spicules – Composed of Silica
EARLY PALEOZOIC LIFE Metazoan Invertebrates Phylum Porifera (sponges) SPICULES Spicules – Composed of Spongin
EARLY PALEOZOIC LIFE Metazoan Invertebrates Phylum Porifera (sponges) Cambrian Protospongia
EARLY PALEOZOIC LIFE Metazoan Invertebrates Phylum Porifera (sponges) Ordovician
EARLY PALEOZOIC LIFE Metazoan Invertebrates Phylum Porifera (sponges) Silurian Caryospongia Astylospongia
EARLY PALEOZOIC LIFE Metazoan Invertebrates Phylum Porifera (sponges) Silurian Palaeomanon
EARLY PALEOZOIC LIFE Metazoan Invertebrates Phylum Porifera (sponges) Silurian Astraeospongia Star-shaped spicules
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
EARLY PALEOZOIC LIFE Metazoan Invertebrates Stromatoporoids Side view Laminae and Pillar Structure
EARLY PALEOZOIC LIFE Metazoan Invertebrates Stromatoporoids Top view
EARLY PALEOZOIC LIFE Metazoan Invertebrates Cnidaria (Coelenterata or Corals) Includes Sea fans Jellyfish Anemones Corals Very diverse group Stinging cells – cnidocytes Radially symmetrical
EARLY PALEOZOIC LIFE Metazoan Invertebrates Cnidaria (Coelenterata or Corals) Fire coral Jellyfish Sea fans, gorgonian Modern corals Horn corals Tabulate corals
EARLY PALEOZOIC LIFE Metazoan Invertebrates Cnidaria (Coelenterata or Corals) Two forms: Polyps and Medusa Polyps – asexual Medusa - sexual
EARLY PALEOZOIC LIFE Metazoan Invertebrates Cnidaria (Coelenterata or Corals) Stinging cells Cnidocytes
EARLY PALEOZOIC LIFE Metazoan Invertebrates Cnidaria (Coelenterata or Corals) Stinging cells or Cnidocytes
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
EARLY PALEOZOIC LIFE Metazoan Invertebrates Rugosa (Rugose or Horn Corals)
EARLY PALEOZOIC LIFE Metazoan Invertebrates Rugosa (Rugose or Horn Corals)
EARLY PALEOZOIC LIFE Metazoan Invertebrates Rugose growth