Lecture 19 Life of the Late Paleozoic Era. Historical Geology Late Paleozoic Life ILate Paleozoic Marine Communities IILate Paleozoic Land Communities

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


Plants

Historical GeologyLate Paleozoic Land Flora


Lycopsids

Lepidodendron stem Lepidostrobus coneBaragwanathia Lycopodium


Sphenopsids

Sphenopsids were segmented spore plants that also achieved giant sizes

Calamites, Annularia

Modern sphenopsids include “horsetails”


The Advantage of Seeds


Seed Ferns

Glossopteris


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


The Amniotic Egg


Reptile Evolution


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


Reptile Evolution - Pelycosaurs

diverse, mammal-like reptiles

originated in the Permian but survived into the Triassic period

Dicynodon

Moschops


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


Reptile Evolution - Therapsid Characteristics

Historical GeologyThe Permian Mass Extinction

Species: 90-95%

Losses


brachiopods

fusulinids

porifera

tabulate corals

rugosecorals

gastropodablastoideacrinoidea

trilobites

bryozoans


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)


13C isotopic shift(Italian Alps)


Reichow et al. Science 2002


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


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)


Climate Change

Documents

Lecture 19 Life of the Late Paleozoic Era. Historical Geology Late Paleozoic Life ILate Paleozoic Marine Communities IILate Paleozoic Land Communities