Life
Early Paleozoic life
Fossil record increases with increase in
fossil hard parts.
Vertebrates evolve.
Animals move onto land.
Vascular plants show up.
Also largest mass extinction EVER.
Precambrian-Cambrian
Invertebrate phyla
Early Cambrian fossils
Early Cambrian fossils
Also found in Vendian.
These were very small and originally
overlooked.
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Proterozoic-Cambrian boundary
The Cambrian explosion
Fossils found all over the world that show
incredible diversity and abundance.
Many animals already highly evolved.
All major phyla found except for Bryozoa.
Occurred in Tommotian epoch.
Some of the animals
Burgess Shale & Chengjiang
Anomalocaris -2 feet long! Top predator of
the early Cambrian.
Many early arthropods
Marella, Opabinia.
Various annelid worms
Hallucigenia.
Earliest Chordates!
Pikaia and Myllokunmingia
Anamalocaris and Hallucigenia
Marella and Opabinia
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Pikaia & Myllokunmingia
What is so special about this?
Very well preserved fossils -
anoxic environment.
Soft bodied and hard bodied organisms.
Animals lived on continental shield BUT did not
fossilize there!
Shows high complexity of species.
Some animals were experimental, while some
have ancestors today
Cambrian trilobites
Cambrian to Ordovician
Ordovician by a 3X increase in biodiversity
over the Cambrian.
Organisms evolved to t new niches.
Epifaunal and infaunal
First record of bioturbation
Protistans
Organisms composed of one cell.
Had hard parts.
Foraminifera
Nummulites
Radiolarian
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Marine Invertebrates -Reef
Builders
Nummulites & Radiolarian
Archeocynathids
Similar to sponges and
corals.
But not either
TWO layered outer
wall.
Evolution of Porifera
Archeocyanthids
Porifera
Cnidaria
Bryozoa
Brachiopods
Phylum Porifera -sponges
THREE layered outer
wall.
Endoderm
Ectoderm
Mesoglea
sponges
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Stromatoporoids
Only found in
Paleozoic.
Related to
sponges.
Phylum Cnideria
Includes corals, sea anemones, sea fans,
jellysh.
Either a medusa or a polyp.
Composed of cnidocytes.
Good for paleoenvironment.
Types of Cnidarians
Medusa & Polyp
Some Paleozoic corals
Bryozoa
Colonial animals -NOT related to corals.
Each animal is called a zooid.
Reef building.
First representative individuals were softbodied in the Precambrian.
Related to PHORONIDA.
These possess lophopohore
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What is a lophophore?
lophophore
U-shaped digestive tract.
Mouth at one end & anus @ the other.
All have a circular fold of the body that
encircles the mouth and tentacles.
A fan-like lter feeding adaptation.
Phoronida
Brachiopods
Bryozoans
Geologic range
Inarticulate.
Articulate.
Also have lophophores related to Bryozoa.
Most abundant and useful Paleozoic fossils.
NOT mollusks.
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morphology
Most were marine, sessile, and epifaunal.
Fossil species predominantly from tropical/
subtropical environments.
Tolerated turbid waters.
Orthids -ordovician
Strophomenids -ordovician
Pentamerid -silurian
Spiriferids -devonian
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Productids -permian
Marine Invertebrates -Mobile
Mollusks
Arthropods
Echinoderms
Mollusks
Amphinuera
Scaphopoda
Monoplacaphora
Bivalvia
Gastropoda
Cephalopoda
Mollusks
Most varied, dominant and successful group
Starts in the Cambrian.
Microscopic to 16m long.
A muscular foot that may be enlarged to
form a head containing a mouth, organs and
sometimes tentacles.
monoplacophoran
They have all the complex organ systems of
complex animals.
All unsegmented, bilaterally symmetrical
animals.
Evolved from annelid worms.
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polyplacophoran
Bivalves
Gastropods
cephalopods
Cephalopod sutures
Arthropoda
Ostrocods
Eurypterids
Trilobites
Insects!
Growth is accomplished by molting -the
rst phylum to do so.
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Eurypterids
eurypterid
The top predator in the Silurian was the
a type of arthropod.
Largest was 6 feet long!
Moved into brackish water in the
Ordovician.
Ostrocods
Ostrocods
Cambrian to recent.
Small, bivalved crustaceans.
may exceed trilobite for biostrat signicance
Live in every aquatic habitat.
Ordovician had the largest diversity.
Fresh water groups evolved in the Devonian.
Mesozoic and Cenozoic groups evolved to
live in brackish and lake environments.
Ostrocod
Trilobites
-Body fossils are not found before late Cambrian.
BUT tracks suggest they were around
-Early Ordovician -2nd trilobite expansion
many anti predator adaptations
Late Ordovician extinction, diversity dropped.
Silurian types were rare.
Middle to Late Devonian -another extinction
event.
Final Blow was at the end of the Permian.
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Phacops rana
Trilobite Anatomy
note the complex eye!
Protapsid, Merapsid, & Holapsid
Trilobite family tree
Insect info
All have jointed appendages.
Not only for walking or swimming, but
some have evolved as mouth parts or
reproductive structures.
All have a chitinous jointed exoskeleton.
some groups have the exoskeleton strengthened
by carbonate.
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More insect info
Insects
Body is segmented- like an annelid worm.
Segments may have become fused into
groups.
Segments perform different functions.
insects
May be rst animal to have moved onto
land.
First evidence in the Silurian.
Largest in carboniferous -2feet wingspan!
Related to O2 levels.
Other Arthropods
Insect history
Silurian -millipedes, spiders, scorpions on land.
Devonian-most primitive, wingless insects.
Mississippian- winged insects-
species that hold wings straight out.
Pennsylvanian-radiation of insects
With wings that fold back age of cockroaches.
Permian-insects w/growth stages (metamorphose).
Jurassic and Cretaceous-
familiar insects evolved.
Tertiary -only one order emerged.
Even more arthropods!
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Echinodermata
Starsh
Brittle stars
Sea urchins
Blastoids & Crinoids
Sea cucumbers
Ankarua
echinoderms
All have a calcitic shell.
Regular or Irregular.
Extending radially from the mouth are
ambulacural grooves.
They can regenerate lost parts.
Pentameral symmetry.
starsh
Found in Ediacaran
fossils.
Small disc fossil.
5 rays on its surface.
Brittlestar
Sea urchins
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Blastoids crinoids
holothoroids
Echinoderm-Vertebrate
connection
Dont & forget the Graptolites
Dueterstomes
Echinoderms, chordates
Protostomes -
Annelids, mollusks, arthropods
Extinct, planktic.
Excellent index
fossils.
Related to chordates.
Chordates
Stiff elongate supporting structure.
Dorsal, central nerve.
Gill slits.
Circulating blood.
Vertebrates!
Animals having a segmented backbone.
Vertebral column
Also possess a cranium that holds the brain.
Two major groups
Non-amniotic
Animals must be in water for fertilization, external
fertilization.
Amniotic
Enclosed egg, internal fertilization.
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Amniotic egg
oldest jawless FISH
FISH
The greatest changes in the Silurian and
Devonian were in the vertebrates.
The Devonian is often called "the age of
shes.
Agnathids (Jawless shes) rst found in
Chengjiang Cambrian.
In the Silurian, they developed armored head
shields and body armor.
They had a slit like mouth and were probably
lter feeders.
Fish Facts
Oldest group of vertebrates.
Fish were the rst group to have a head!
First to have pairs of sense organs; two eyes
for binocular vision, two ears to localize
sounds and twinned nostrils.
Fish were the rst to wear their senses in
sets.
Fish history
Also rst to have paired appendages ns!
These will evolve into biceps, triceps,
rotating wrists and opposable thumbs.
AND jaws, including enameled teeth; and a
tongue!
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Acanthodians -rst sh to possess features
of modern sh.
Jaw and ear bone evolution.
The rst jawed sh were the placoderms.
They had large eyes, a strong bite and were
good swimmers and the TOP predator.
Jaw evolution
These also had cartilage skeletons but also had bony
armor down to their ns, the largest being the
Dunkleosteus and reached 40ft in length.
Ear bone
evolution
Chondrichthyes
Fish with cartilaginous skeleton.
Dunkleosteus
Paleozoic sh
The rst true sharks were in this group,
whose skeleton is completely made of
cartilage. The largest reached 4ft in length.
Osteichthyes
Fish with bone skeleton.
Important for evolution of tetrapods.
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Paleozoic sharks
Except for the sharks, most of these species
did not survive the Devonian, only the
acanthodians lasted into the Permian.
Fish!
Two groups arose in the Devonian
and have living descendants.
Ray nned sh -ourished during the late Paleozoic,
today 99% of all sh are from this group. The ns are
supported by bony spines radiating from their bodies.
Lobe nned sh -club shaped n supported by stout bones
homologous to our bones! Eventually this allowed the
sh to walk on land.
These sh also had internal nostrils and eventually lungs
allowing them to breath out of water. There are 3 groups
of lobe ns left; the lungsh, coelacanth, and the lineage
that led to amphibians.
Crossopterygerians
Ancestors of amphibians.
Evolved from lobe-nned sh.
Adaptations let the animal live in very shallow
water and move from one water body to another.
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Amphibian and Crossopterygian
coelacanth
Lobe-nned sh & Tetrapods!
amphibians
The rst amphibians appeared on dry land at
the end of the Devonian.
Animals had to deal with the problems of
drying out, support and reproduction.
Amphibians still reproduce in the water, but
developed strong limbs and semi-permeable
skin.
Ichthyostega is a transitional species between
sh and amphibians
By the Carboniferous, amphibians lost a lot of
their shlike features.
Tiktaalik
Fish to Ichthyostega
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Fun fact
Crossoptyergian & Ichthyostega
From sh to amphibians
Necks evolved!!
Ichthyostega
Amniotes -Carboniferous
Reptiles
Dinosaurs
Birds
Mammals
History of Amphibians
End of Devonian- rst amphibians crawled onto
land i.e. Ichthyostega.
Carboniferous- amphibians were the largest
animals.
Permian- large at bodied temnospondyl
amphibians reached crocodile size (7ft long,
290lbs).
Another group, anthrocosaurs had deep skulls
and walked higher than the other groups. This
group was very "reptilian", and lived well into the
Permian.
Pennsylvanian-
ammoniates split into 2 groups
Reptiles -began with small lizardlike
animals and diversied into turtles, marine
reptiles, lizards & snakes, and crocodiles,
dinosaurs & birds.
Synapsids- "mammal-like reptiles" from
which mammals evolved.
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Dimetrodon -a therapsid
Therapsids
Cynognathus
Conodont animal
Ranged from 15-50mm.
Large movable eyes.
Originally thought to be a predator but
lateral position of the eyes makes that idea
unlikely.
Notochord.
Dorsal nerve cord.
Possible cellular bone -and thus vertebrate.
Related to synapsids.
Similarities with mammals.
Fewer skull bones than reptiles.
Complex jaw and teeth differentiation.
Had fur.
Possibly endothermic.
Conodonts
LAND PLANTS!!
Up to the Ordovician the only plants on land were
macrobiotic crusts.
During the Devonian, the rst fossils were
emerging from swamps.
Upper Ordovician fossil spores have been found
of spores -indicating that more advanced plants.
Burrows of the same age indicate that
invertebrates were living among the vegetation.
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Evolution of vascular plant
Evolution of gymnosperm
Cooksonia
Aglaophyton
Rhynia
Lycopsids
Vascular plants are
rst found in the late
Silurian.
These had spore
bearing organisms
called sporangia at
their tips.
Late Devonian.
Includes living club
mosses.
Sporangia are arranges
in tight clusters called
cones.
Male & female plants
often separate.
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Sphenopsids
So, in the Paleozoic
All vascular plants produced spores
No SEEDS.
There are NO FLOWERS yet.
All plants live NEAR water or warm, moist
environments.
Think of ferns at the present time
So, what is happening to the 02?
Glossopteris -a seed plant!
True ferns
First seed plants
Late Devonian.
The rst species were called seed ferns
because of their foliage.
This is an important step because seeds do
not need water to fertilize.
In the Late Devonian the landscape was
covered with trees 33ft tall and varied
species of plants.
Ginkgos
True seeds.
Lived in subpolar to
temperate environments.
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extinctions
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