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Eons

Eons

Hadean, Archean, Proterozoic, Phanerozoic

Eras of the Phanerozoic Eon

Paleozoic, Mesozoic, Cenozoic

Cenozoic Periods

Paleogene, Neogene, Quaternary

Mesozoic Periods

Triassic, Jurassic, Cretaceous

Paleozoic Periods

Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian

Biggest to smallest time scale

eon, era, period, epoch

What conditions limited diversity in ediacaran?

low atmospheric O2 and 2 glaciation

atmospheric O2 rising after glaciation during warming

predation forcing natural selection

Character of late precambrian ecological niches

-no continental biota (intense weathering)

-rodinia supercontinent

-shallow marine dominated by stromatolite mats

fossils were benthic or platonic (no burrowing)

-vertebrate fishes appear

planktonic

Describes bacteria that are freely floating in water.

benthic

bottom of an aquatic ecosystem; consists of sand and sediment and supports its own community of organisms

Cambrian period: overcoming the challenges to multi-cellular life

size limiting factor (low O2)

snowball earth

after last snowball earth

late Proterozoic

stabilization of climate (clement conditions)

end of Paleozoic orogenies

break up of rodinia

large igneous provinces

What caused Caused the Cambrian explosion

drastic reorganizing of substrate ecology

rise of predation

rising O2 levels

Ediacaran fossils

mostly benthic or planktonic

no indication of substrate burrowing

Ediacaran marine environments

shallow environments were covered in algal mats

this hindered development of varied ecological niches and suppressed diversification

decomposing alge

decomposing algal mats may have created sporadic anoxic conditions on ocean floor

burrowing worms

Trichophycus pedum

biologic marker for beginning of Cambrian

Kingdom Protista (since Archean)

eukaruota

single celled with exoskeleton for protection

foraminifera

marine protist

CaCO3 exoskeleton

1-2 inches

diverse

present since Cambrian

radiolaria and diatoms

mid cretaceous

protist

exoskeleton made of silica

Life forms appearance in Cambrian explosion

Invetebrates

vertebrates

types of invertebrates in order

Bryozoa

brachiopods

arthropods

echinoderms

hemichordates

types of arthropods

crustaceans

mollusks

insects

arachnids

vertebrates

type of horde

one of the earliest progenitors

Phylum Porifera

sponges

vessel shaped

full body pores to Chanel water and circulated

produce hard mineral called spicules

diverse

since Cambrian

filter feederes

sessile

reef building sponges

Phylum Cnidara

soft bodies metazoans, sac like

filter feeders

jelly fish

coral

corals

group of cnidaria

consist of plolyp that builds mineralized theca

fossilize easily

Phylum Brachiopoda

"strong short arm"

new in Cambrian

shallow marine invertebrates

clams

vertical symmetry

filter feeds

reef builders

benthic or burrowers

Phylum Mollusca

soft bodies

marine, freshwater, or terrestrial

swim flat or drift

burrow bore or crawl

three classes

classes of Mollusca

bivalves (clams)

gastropods (snail)

cephalopod (squid)

Phylum arthropoda

one of largest phylum

shellfish and molluska

crustacea

shellfish and molluska

elongated bodies and soft shells

family include

barnacles

crabs

crayfish

lobster

prawns

shrimp

land snails

subclass ostracod