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Lecture 19
Life of the Late Paleozoic Era
Historical GeologyLate Paleozoic Life
I Late Paleozoic Marine CommunitiesII Late Paleozoic Land Communities
A) Plants1) Spore-bearing Plants2) Gymnosperms
B) Metazoans (Animals)1) Reptiles2) The Amniotic Egg
III The Permian Mass Extinction
Late Paleozoic Life
Historical GeologyLate Paleozoic Marine Communities
Historical Geology
Phylum: Echinodermata
Class: Crinoidea
Late Paleozoic Marine Communities
Historical GeologyLate Paleozoic Marine Communities
Petremites
Phylum: Echinodermata
Class: Blastoidea
Productid Brachiopods
index fossils for the Permian period
spines were attached at raised bumps found on fossil shells
Historical GeologyHistorical GeologyLate Paleozoic Marine Communities
Historical GeologyLate Paleozoic Marine CommunitiesFusulinids
Kingdom: Protista
Historical GeologyLate Paleozoic Life
Plants
Historical GeologyLate Paleozoic Land Flora
Historical GeologyLate Paleozoic Land Flora
Lycopsids
Lepidodendron stem Lepidostrobus coneBaragwanathia Lycopodium
Historical GeologyLate Paleozoic Land Flora
Sphenopsids
Sphenopsids were segmented spore plants that also achieved giant sizes
Calamites, Annularia
Modern sphenopsids include “horsetails”
Historical GeologyLate Paleozoic Land Flora
The Advantage of Seeds
Historical GeologyLate Paleozoic Land Flora
Seed Ferns
Glossopteris
Historical GeologyLate Paleozoic Life
Insects
Insects had appeared in Devonian time
Wingless forms
Insects underwent evolutionary radiation in Carboniferous time
Primitive winged forms (dragon flies)
Forms with folding wings
Historical GeologyLate Paleozoic Life
The Amniotic Egg
Historical GeologyLate Paleozoic Life
Reptile Evolution
Historical GeologyLate Paleozoic Life
Reptile Evolution
The carnivore Dimetrodon
The herbivore Edaphosaurus
evolved from the protorothyrids during the Pennsylvanian
the dominant reptile group by the Early Permian
evolved into a diverse assemblage
Historical GeologyLate Paleozoic Life
Reptile Evolution - Pelycosaurs
diverse, mammal-like reptiles
originated in the Permian but survived into the Triassic period
Dicynodon
Moschops
Historical GeologyLate Paleozoic Life
Reptile Evolution - Therapsids
small- to medium-sized animals
displaying many mammalian features
fewer bones in the skull due to fusion of many of the small skull bones
enlargement of the lower jawbone differentiation of the teeth for various functions such as nipping,
tearing, and chewing food and a more vertical position of the legs for greater flexibility, as opposed to the sideways sprawling legs in primitive reptiles
Historical GeologyLate Paleozoic Life
Reptile Evolution - Therapsid Characteristics
Historical GeologyThe Permian Mass Extinction
Species: 90-95%
Losses
Historical GeologyThe Permian Mass Extinction
brachiopods
fusulinids
porifera
tabulate corals
rugosecorals
gastropodablastoideacrinoidea
trilobites
bryozoans
Historical GeologyThe Permian Mass Extinction
Global Cooling (Glaciation
Marine anoxia began in Late Permian, extended through Early Triassic
Negative shift in d13C values at extinction level (continental and marine sections)
Age of massive Siberian flood basalts is same as extinction
Climatic warming and drying near extinction level
Rapid Sea Level Oscillations
Deep-sea anoxic interval (Japan)
Historical GeologyThe Permian Mass Extinction
13C isotopic shift(Italian Alps)
Historical GeologyThe Permian Mass Extinction
Reichow et al. Science 2002
Historical GeologyThe Permian Mass Extinction
Siberian Flood Basalts
45 identified lava flows
400m to 3,700m thick
Volume of 1.5 to 3 × 106 km3
Duration of eruptions was only ~600 ky
Historical GeologyThe Permian Mass Extinction
Siberian Flood Basalts
Change from meandering to braided river systems in South Africa and Urals
Reduction in bank-stabilizing vegetation Widespread charcoal horizons, desert sedimentation, warm indicators
in paleosols (China, Australia, Antarctica)
Abrupt change from Glossopteris- to Dicroidium-dominated floras (Australia)
Historical GeologyThe Permian Mass Extinction
Climate Change
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