Late Paleozoic Life

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)