Lecture 19
Life of the Late Paleozoic Era
Historical Geology
I
II
A)
B)
III
Late Paleozoic Life
Late Paleozoic Marine Communities
Late Paleozoic Land Communities
Plants
1)
2)
Spore-bearing Plants
Gymnosperms
1)
2)
Reptiles
The Amniotic Egg
Metazoans (Animals)
The Permian Mass Extinction
Late Paleozoic Life
Historical Geology
Late Paleozoic Marine Communities
Historical Geology
Late Paleozoic Marine Communities
Phylum: Echinodermata
Class: Crinoidea
Historical Geology
Late Paleozoic Marine Communities
Phylum: Echinodermata
Class: Blastoidea
Petremites
Historical Geology
Late Paleozoic Marine Communities
Productid Brachiopods
index fossils for the Permian period
spines were attached at raised bumps
found on fossil shells
Historical
Geology
Late Paleozoic
Marine
Communities
Fusulinids
Kingdom: Protista
Historical Geology
Late Paleozoic Life
Plants
Historical Geology
Late Paleozoic Land Flora
Historical Geology
Late Paleozoic Land Flora
Lycopsids
Lepidodendron stem
Baragwanathia
Lepidostrobus cone
Lycopodium
Historical Geology
Late Paleozoic Land Flora
Sphenopsids
Sphenopsids
were segmented
spore plants
that also
achieved giant
sizes
Calamites,
Annularia
Modern
sphenopsids
include
“horsetails”
Historical Geology
Late Paleozoic Land Flora
The Advantage of Seeds
Historical Geology
Late Paleozoic Land Flora
Seed Ferns
Glossopteris
Historical Geology
Late 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 Geology
Late Paleozoic Life
The Amniotic Egg
Historical Geology
Late Paleozoic Life
Reptile Evolution
Historical Geology
Late Paleozoic Life
Reptile Evolution
Historical Geology
Late Paleozoic Life
Reptile Evolution - Pelycosaurs
evolved from the
protorothyrids during
the Pennsylvanian
The herbivore
Edaphosaurus
the dominant reptile
group by the Early
Permian
evolved into a diverse
assemblage
The carnivore
Dimetrodon
Historical Geology
Late Paleozoic Life
Reptile Evolution - Therapsids
Moschops
Dicynodon
diverse, mammal-like reptiles
originated in the Permian but survived into the Triassic period
Historical Geology
Late Paleozoic Life
Reptile Evolution - Therapsid Characteristics
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 Geology
The Permian Mass Extinction
Losses
Species: 90-95%
Historical Geology
The Permian Mass Extinction
fusulinids
tabulate
corals
trilobites
crinoidea
rugose
corals
brachiopods
blastoidea
bryozoans
porifera
gastropoda
Historical Geology
The 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
Historical Geology
The Permian Mass Extinction
Deep-sea
anoxic interval
(Japan)
Historical Geology
The Permian Mass Extinction
13
d C
isotopic
shift
(Italian
Alps)
Historical Geology
The Permian Mass Extinction
Siberian Flood Basalts
Reichow et al.
Science 2002
Historical Geology
The 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 Geology
The Permian Mass Extinction
Climate Change
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)