GEOL 1003 Midterm: GEOLOGY EXAM 4 Ch 15
CH. 15 The LATE Paleozoic Era: Carboniferous and
Permian Periods
Overview of Carboniferous Period:
•Divided into TWO sub-periods:
oThe Mississippian: time of extensive limestone deposition
oThe Pennsylvanian: a Time of extensive coal formation from burial of spore
trees/pants that grew in swamps
•Carboniferous Glaciation-- Glaciers spread during climactic change
Overview of Permian Period:
•Glaciers receded
•Major tectonic events-mountain building at Applachians and Ouachitas
oFormation of PANGEA supercontinent
•Very DRY climate
oReduction of coal swamps
oIncrease in evaporite deposition
oExtinction of many spore plants
oExtinction of many amphibians
oThis left world open with SEED plants and mammal-like therapsids
•END of an ERA: the most catastrophic mass extinction of all the Phanerozoic Eon.
oTwo major biotic crises:
•1st= Guadalupian mass extinction
•2nd= Terminal Permian mass extinction
Life In the LATE Paleozoic
1. INTRO to LIFE in late Paleozoic
oLife in Marine Realm:
•Essentially same as Devonian
•Main difference is appearance of NEW REEF BUILDERS
oLife on Land:
•Many changes occurred:
Numerous insects of modern appearance evolved
Many new kinds of spore trees colonized broad swamps
Due to ARID climate of Permian -- Spore trees and amphibians
decreased
Seed trees dominated during Permian
Terrestrials reptiles rose to dominance over amphibians
Later, terrestrial therapsids(mammal-like) became dominant
land vertebrates
1. Life in the Late Paleozoic SEAS
oSOME species never recovered from DEVONIAN mass extinction:
•Tabulate Corals
•Stromatoporoids
Both's roles became minor to marine-life.
oOTHERS re-diversified quickly and became prominent!
1. Ammonoids (swimmers)
Abundant & Diverse so extremely useful to date LATE PALEOZOIC
sections
Light shells indicate high mobility
1. Sharks & Ray-fin Bony Fish out compete armored fish
They were DIVERSE and ABUNDANT in late Paleozoic
The TOP MARINE PREDATOR
Armored placoderms (very common in Devonion seas) became extinct in
the Carboniferous
•Most other armored forms ( fish with heavy & slow
shells=nautiloids) disappeared as well-> replaced by mobile life
forms
Suggests that swimming fast became a survival necessity
1. Brachiopods
They rebounded from the late Devonian extinction and resume a
PROMINENT ecological role
Productids are most successful group who were small spiny
brachiopods
Cone-shaped shell
Anchored and protected themselves w/ SPINES
1. Crinoid MEADOWS
Crinoids became very abundant and diverse in
CARBONIFEROUS
They formed meadows
These are Sea-Lilies are animals that were attached to the
seafloor
•Capture floating food that came w/in reach of arms
Segmented stalks that broke into disk segments that play HUGE
role in Carboniferous limestone (mississippi valley)
1. Bryozoans
The second animal group that was IMPORTANT to the formation
of the mississippi LIMESTONE
Sheet-like colonial ANIMALS who stood upright and were size of
ferns
Fed on suspended organic matter
1. Fusulinids
Very large foraminifera (Protists) that lived on shallow
seafloor
Single-celled amoeba-like creatures w/ shells ( up to 4cm
long!)
Underwent ENORMOUS Late Carboniferous radiation
There's more than 5000 species from the Permian alone
Used as guide fossils for upper Carboniferous//Permian
Periods
Contributor to limestone as well
1. Aragonitic Reef Builders Flourished in Aragonite Seas
oIn Carboniferous the Mg/Ca ratio in the sea was high
•Due to decreased size of the MidOceanRidge (less Mg absorbed by
MOR; Less Ca release from MOR)
oAs a consequence: calcite seas from mid-Paleozoic gave way to Argonite Seas
of the Late-Paleozoic
oOnly few organisms can build reefs with HIGH Mg in ocean and low Ca
•The TWO main Aragonitic Reef Builders of the LATE-Paleozoic were:
Aragonitic Algae
•Important REEF builder of LATE CARBONIFEROUS
Aragonitic Sponges
•Important REEF builder of PERMIAN reefs
1. Trees Grew in Late Carboniferous Swamps
oPlant remains give the Carboniferous Period its name
oNo other Geologic periods contain as many plant fossils like:
•Spore and Pollen
•Stems
•Leaves
•Roots
oThis was a time of Enormous plant biomass production in swamps
•Given the enormous volume of Carboniferous coal beds, the wetlands
were highly more VAST than today
•The Biomass was dominated by TWO key genera
oThe TWO dominant Coal Swamp Plants were Two Genera of LYCOPODS:
•Lepidodendron
The most successful of two genera
Grew up to 30m tall; 1m wide across base
SPORE plant= limited to wet environment
Trunk had spiral pattern of scars where leaves were attached
•Sigillaria
Spore plant genus= limited to Wet environments
Trunk had vertical columns of leaf scars
oFerns Constituted the Undergrowth of tree-like Lycopods
•They were abundant
•Composed of:
Spore ferns (like modern ferns)
Seed ferns (ferns that produced seeds)
•A few-fern grew as large as a tree: Glossopteris is the most famous tree-
like seed fern
1. Upland Floras Expanded in the LATE Carboniferous
oSpore Plants called SPHENOPSIDS occupied higher ground areas:
oGymnosperms (naked seed plants) became the dominant woodland plant of
the PERMIAN
•It was better adapted to increasingly DRY climate of the PERMIAN
•Walchia, an early conifer from the LATE Carboniferous age
Had needled branches and reproduced by means of "cones"
Living conifer species related REDWOODS
1. Animals Invaded Freshwater Habitats and Diversified on Land
oSeveral animals diversified and populated FRESHWATER habitats
•Ray-fin Fish
•Fresh-water Sharks
•Mollusks (clams)
Document Summary
Overview of permian period: glaciers receded, major tectonic events-mountain building at applachians and ouachitas, formation of pangea supercontinent, very dry climate, reduction of coal swamps. Intro to life in late paleozoic: life in marine realm: Main difference is appearance of new reef builders: life on land: Many new kinds of spore trees colonized broad swamps. Due to arid climate of permian -- spore trees and amphibians. Life in the late paleozoic seas: some species never recovered from devonian mass extinction: Both"s roles became minor to marine-life: others re-diversified quickly and became prominent! Abundant & diverse so extremely useful to date late paleozoic sections. Sharks & ray-fin bony fish out compete armored fish. They were diverse and abundant in late paleozoic. Armored placoderms (very common in devonion seas) became extinct in the carboniferous: most other armored forms ( fish with heavy & slow shells=nautiloids) disappeared as well-> replaced by mobile life forms. Suggests that swimming fast became a survival necessity.
