The Modern fauna - the great carnivore crisis

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The Modern fauna - the great carnivore
crisis 1. Sepkoskis Curves 2. The Modern
fauna 3. Bivalves 4. Ammonites 5.
Gastropods 6. Echinoids 7. Ecological
overview
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1. Sepkoskis Curves
Family diversity
Modern fauna
End Permian extinction
Ordovician radiation
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2. Modern fauna
Many active predators
Simple brachiopods
Intense burrowing below sea floor
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3. Bivalves
Bivalves are molluscs with two shells. Most
filter feed and live infaunally.
Shell
Mantle, with inhalent and exhalent siphons
Foot
Burrowing adopted as lifestyle in Jurassic.
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4. Ammonites
Swimming, predatory molluscs with a coiled,
external shell. True ammonites had complicated
sutures between segments of their shell and are
only found in the Mesozoic.
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5. Gastropods
Predatory, grazing or scavenging molluscs
Inhalent siphon mantle extension used to direct
water to gills (within mantle cavity)
Mouth, with rasping radula
Foot flattened muscular foot used for locomotion
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6. Echinoids
Echinoderms with internal, calcareous skeleton
comprised of multiple plates. Begin to burrow in
Jurassic
Madreporite highly perforated plate through
which seawater is bought into water vascular
system.
Aristoles Lantern movable skeletal plates that
act like jaws.
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7. Ecological overview
1. Modern fauna is most diverse marine community
of Phanerozoic. 2. Diversity rises to around
600 families 3. A wide range of primary
consumers 4. Tiered above and below seabed 5.
Highly diverse array of predators 6. Recovered
best from end Permian extinction, perturbed but
not fundamentally affected by end Cretaceous
event.