Carboniferous

What was the time scale for the Carboniferous?

359-299 mya

Carboniferous
Period Key events:

Carboniferous
Period Key events:
– Abundant
swamps
– Later glaciation
• Permian drying

Late Paleozoic
• Life in the ocean mostly similar, except for
changes in reef composition

Significant changes to life on land:

Significant changes to life on land:
-insects
-seedless trees colonize extensive swamps during
Carboniferous
-Permian was much dryer, led to a change in
terrestrial plant and animal communities
-End-Permian time saw terrestrial vertebrates with
new adaptations for feeding and locomotion,
similar to today’s mammals

Late Paleozoic Life in the Sea

Late Paleozoic Life in the Sea
• Mostly similar to
Mid-Paleozoic
marine life

Marine life

• Marine
• Mid-Paleozoic reef-
formers never
recovered; coral-
strome communities
were never
significant

Brachiopods

– Brachiopods
• Productids
• Cone-shaped
shells
• Produced reefs

Ammonoids

Ammonoids:
abundant
• Highly mobile
• Widespread

—>Index fossils

Crinoid meadows

Crinoid meadows
– Significant
contribution to
early
Carboniferous
(Mississippean)
limestone
– Passive debris
catchers, eaters
– Abundant
—>Index fossils

Mobile predators like sharks, ray-finned, bony fish:

Mobile predators like
sharks, ray-finned,
bony fish

-abundant
-Shifted food web

-Armored placoderms
die out

Bryozoans

Bryozoans
– Sheetlike colonial
animals
– Trapped sediment
in mounds
– Important
contribution to
limestone

Fusulinids

Fusulinids
– Foraminifera
– Late Carboniferous
radiation
– Up to 10 cm in length;
SINGLE CELLED!
– Guide fossil for Upper
Carboniferous and
Permian

Late Paleozoic Life in the Sea

Late Paleozoic Life in the Sea
• Higher Mg-Ca ratio favors
aragonite precipitation
• Aragonitic algae
– Important in late
Carboniferous reefs
• Aragonitic sponges
– Played important role in
Permian reefs

More significant changes to life on land

More significant changes to life on land
• Extensive swamps developed
• Coal swamps dominated by lycopods –club mosses
– Lepidodendron
• Up to 30 m tall
– Sigillaria

-Both seedless, Vascular plants
-Fall over, accumulate in swamp, form coal seams

-No termites yet, Allowed dead wood To accumulate

-Lepidodendron most Successful of two
-Grew far apart, didn’t Provide significant shade

Upland faunas

Upland faunas:

-Gymnosperms, or naked-seed plants

-Seeds lodged in exposed position on cones

- Conifers (cone- bearing trees)
- Cycads; occupy tropics today
- Ginko biloba only extant representative of 3rd kind of
gymnosperm

Late Paleozoic Life on Land

Late Paleozoic Life on Land
Terrestrial life diversified, invaded freshwater
-ray-finned fish diversified, joined freshwater sharks (no living relatives)
-mollusks abundant in freshwater habitats
-insects with wings!

Winged insects

Winged insects:

wings don’t fold on body, always stick out
– Dragonflies
– Mayflies

Suggests higher atmospheric oxygen concentrations..?

-Amphibians were larger, hard to tell if strictly terrestrial
-not completely covered in scales, which is true of later terrestrial animals

Reptiles

Reptiles
– Requires amniote egg
– Protects embryo
– No longer needs water for development

-coo-evolution of
seed plants and
reptiles = fully
terrestrial lifestyle
– Advanced jaws could apply pressure, slice
– Faster, more agile than amphibians
—>Chase their
prey; constantly evolving predator/prey relationships

Pelycosaurs

Pelycosaurs
– Dimetrodon
• Ancestor of therapsids; finback predator; swampy.

– Complex jaws
– Endothermic

Why is being warm blooded important?

Warm-blooded; can chase prey, evade other predators

Therapsids

Therapsids
– Similar to mammals
– Legs no longer sprawling
– Complex jaws
– Endothermic
• Warm-blooded; can chase prey

Late Carboniferous

Late Carboniferous
-Pangaea forms
-Alleghenian orogeny;
Appalachian Mtns,
Ouachita Mtns
-expansion of ice sheets

Late Paleozoic Paleogeography

Late Paleozoic Paleogeography
-Continents clustered
near each other

• Early Carboniferous
– High sea level
– Warm, shallow seas
• Abundant limestone
• Evaporites on western
North American
continent
• Coal swamps in NE
Euramerica

Mid-Carboniferous

Mid-Carboniferous
– Mississippian to Pennsylvanian transition marked by expanded glaciation
– Erosional surface; unconformity
– Mass extinction

what led to major glaciation?

Burial of cycads, trees, ferns in “coal swamps” that
spread across floodplains of eastern Euramerica lead
to major glaciation; lag of evolution of termites,
organisms that decompose wood helps bury carbon

—> Forms massive coal deposits

Mid-carboniferous

Mid-carboniferous
– Mississippian
– Pennsylvanian
• Gondwanaland collided with Eurasia
• Hercynian orogeny in Europe, Alleghenian orogeny in N America
– Extended Appalachians
• Alleghenian mountains

-Formed Ouachita Belt
• Oklahoma, Texas
– Glaciers; Sea level drops

Later Carboniferous

Later Carboniferous
– Increased latitudinal gradients impact which kinds of sediments accumulate in different regions

– Glaciation expanded to the equatorial region; NE Colorado has huge freeze/thaw cracks as are found in modern glacial environments

Early Carboniferous

• Early Carboniferous
– High sea level
– Warm, shallow seas
• Abundant limestone
• Evaporites on western North American continent
• Coal swamps in NE Euramerica