History of Life

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History of Life
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I. Earth History
4.5 bya Earth Forms
4.0 bya Oldest Rocks
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I. Earth History
4.5 bya Earth Forms
4.0 bya Oldest Rocks
3.5 bya Oldest Fossils
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IV. Early Life - the first cells were probably
heterotrophs that simply absorbed nutrients and
ATP from the environment. - as these substances
became rare, there was strong selection for cells
that could manufacture their own energy storage
molecules. - the most primitive cells are
methanogens, but these are NOT the oldest
fossils.
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IV. Early Life - the second type of cells were
probably like green-sulphur bacteria, which used
H2S as an electron donor, in the presence of
sunlight, to photosynthesize.
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I. Earth History
4.5 bya Earth Forms
4.0 bya Oldest Rocks
3.5 bya Oldest Fossils
Stromatolites - communities of layered 'bacteria'
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IV. Early Life - the evolution of oxygenic
photosynthesis was MAJOR. It allowed life to
exploit more habitats, and it produced a powerful
oxidating agent! These stromatolites, which date
to gt 3 bya are microbial communities.
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I. Earth History
2.3-2.0 bya Oxygen in Atmosphere
4.5 bya Earth Forms
4.0 bya Oldest Rocks
3.4 bya Oldest Fossils
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IV. Early Life - about 2.3-1.8 bya, the
concentration of oxygen began to increase in the
ocean and oxidize eroded materials minerals...
deposited as 'banded iron formations'.
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I. Earth History
2.3-2.0 bya Oxygen
1.8 bya first eukaryote
4.5 bya Earth Forms
4.0 bya Oldest Rocks
3.4 bya Oldest Fossils
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IV. Early Life - 2.0-1.7 bya - evolution of
eukaryotes.... endosymbiosis.
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IV. Early Life
Eukaryote Characteristics - membrane bound
nucleus - organelles - sexual reproduction
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I. Earth History
2.3-2.0 bya Oxygen
1.8 bya first eukaryote
0.9 bya first animals
4.5 bya Earth Forms
4.0 bya Oldest Rocks
3.4 bya Oldest Fossils
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I. Earth History
2.3-2.0 bya Oxygen
1.8 bya first eukaryote
0.9 bya first animals
0.5 bya Cambrian
4.5 bya Earth Forms
4.0 bya Oldest Rocks
3.4 bya Oldest Fossils
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I. Earth History
2.3-2.0 bya Oxygen
1.8 bya first eukaryote
0.9 bya first animals
0.5 bya Cambrian
0.24 byaMesozoic
4.5 bya Earth Forms
4.0 bya Oldest Rocks
3.4 bya Oldest Fossils
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I. Earth History
2.3-2.0 bya Oxygen
1.8 bya first eukaryote
0.9 bya first animals
0.5 bya Cambrian
0.24 byaMesozoic
0.065 byaCenozoic
4.5 bya Earth Forms
4.0 bya Oldest Rocks
3.4 bya Oldest Fossils
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I. Earth History
4.5 million to present
(1/1000th of earth history)
2.3-2.0 bya Oxygen
1.8 bya first eukaryote
0.9 bya first animals
0.5 bya Cambrian
0.24 byaMesozoic
0.065 byaCenozoic
4.5 bya Earth Forms
4.0 bya Oldest Rocks
3.4 bya Oldest Fossils
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I. The "Precambrian"
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I. The "Precambrian"
Vendian - 610 mya - 544 mya.
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I. The "Precambrian" - The Ediacaran
(610-544) The first fossil animals
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I. The "Precambrian" - The Ediacaran
(610-544) The first fossil animals
Dicksonia - thought to be a segmented worm
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I. The "Precambrian" - The Ediacaran
(610-544) The first fossil animals
Eoporpita - Cnidarian polyp
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I. The "Precambrian" - The Ediacaran
(610-544) The first fossil animals
Cyclomedusa - Cnidarian polyp up to 1 meter in
diameter
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I. The "Precambrian" - The Ediacaran(610-544) Th
e first fossil animals
Charnia - sea pen (related to Cnidarians) - up to
1 m long
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I. The "Precambrian" - The Ediacaran
(610-544) The first fossil animals
Nemiana - may be a cnidarian or algal colony...
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I. The "Precambrian" - The Ediacaran
(610-544) The first fossil animals
Pteridinium - cnidarian???
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I. The "Precambrian" - The Ediacaran
(610-544) The first fossil animals
Arkarua - Echinoderm?
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Spriggina
I. The "Precambrian" - The Ediacaran
(610-544) The first fossil animals
Spriggina - soft-bodied, but assignment to
Annelida is doubtful... some describe it as a
soft-bodied arthropod...(it is similar to
trilobites...)
trilobite
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I. The "Precambrian" - The Ediacaran
(610-544) The first fossil animals
Tribrachidium - soft-bodied, but enigmatic...
maybe a cnidarian or an echinoderm..???
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I. The "Precambrian" - The Ediacaran
(610-544) The first fossil animals
Kimberella - recent analysis suggest it might be
an early mollusc.. a bit chiton-like...
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I. The "Precambrian" - The Ediacaran
(610-544) The first fossil animals Largely a
radiation of soft-bodied forms. In addition,
however, the first predatory animals
(Cnidarians...) So, although rare, there is a
radiation of soft-bodied organisms before the
Cambrian... and representatives from several
major phyla (or sister phyla) appear.
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals - representatives of nearly all
modern phyla (no Bryozoans) - representatives
of extinct phyla - radiation of animals with
hard parts
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals examples of extant phyla
Thaumaptilon Sea Pen - Cnidaria
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals examples of extant phyla
Sydneyia - Arthropod
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals examples of extant phyla
Canadia - Annelida
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals examples of extant phyla
Choia - Porifera
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals examples of extant phyla
Aysheaia - Onychophora
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals examples of extant phyla
Ottoia - Priapulida
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals examples of extant phyla
Canadapsis - Arthropoda (Crustacea)
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals examples of extant phyla
Waptia - Arthropoda (Crustacea)
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals examples of extant phyla
Leanchoilia - Arthropoda (Crustacea)
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals examples of extant phyla
Pikaia - Chordata
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals examples of extant phyla
Hallucigenia - Onychophora
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals examples of EXTINCT phyla or
subphyla
Olenoides Trilobita (Arthropoda)
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals examples of EXTINCT phyla or
subphyla
Marella - primitive Arthropod
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals examples of EXTINCT phyla or
subphyla
Haplophrentis - Hyolithid
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals examples of organisms unassigned to
any major group
Opabinia
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals examples of organisms unassigned to
any major group
Amiskwia
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals examples of organisms unassigned to
any major group
Anomalocaris
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - an 'explosion' of fossil
animals examples of organisms unassigned to
any major group
Wiwaxia
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) Burgess Shale Community
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya)
WHY?
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - First major radiation of
hard-bodied org's
WHY?
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - First major radiation of
hard-bodied org's Sampling Error? Since
hard-parts fossilize better than soft parts, is
the 'Explosion' just a reflection of the greater
likelyhood of fossilization?
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - First major radiation of
hard-bodied org's Sampling Error? Since
hard-parts fossilize better than soft parts, is
the 'Explosion' just a reflection of the greater
likelihood of fossilization? Predation? The
Vendian radiation contained lots of
predators..Cnidarians. Hard parts would be
adaptive protection against these predators, as
well as the predators in the Cambrian.
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - First major radiation of
hard-bodied org's Sampling Error? Since
hard-parts fossilize better than soft parts, is
the 'Explosion' just a reflection of the greater
likelihood of fossilization? Predation? The
Vendian radiation contained lots of
predators..Cnidarians. Hard parts would be
adaptive protection against these predators, as
well as the predators in the Cambrian.
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - First major radiation of
hard-bodied org's Sampling Error? Since
hard-parts fossilize better than soft parts, is
the 'Explosion' just a reflection of the greater
likelihood of fossilization? Predation? The
Vendian radiation contained lots of
predators..Cnidarians. Hard parts would be
adaptive protection against these predators, as
well as the predators in the Cambrian. Also,
it's important to realize that this "Explosion"
occurred over 10 my.... not 'instantaneous'...

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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - First major radiation of
hard-bodied org's Our first example of
innovation, radiation, and competitive
contraction
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - First major radiation of
hard-bodied org's Our first example of
innovation, radiation, and competitive
contraction
Hard parts
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - First major radiation of
hard-bodied org's Our first example of
innovation, radiation, and competitive
contraction
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II. The Paleozoic Era A. The Cambrian Period
(544 - 510 mya) - First major radiation of
hard-bodied org's Our first example of
innovation, radiation, and competitive
contraction
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I. The Precambrian - Vendian II. Paleozoic
A. Cambrian - The Cambrian 'Explosion' -
The Cambrian Fauna and Beyond
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- The Cambrian Fauna and Beyond The fauna was
dominated by trilobites...
and the number of trilobite families peaked in
the late Cambrian and declined through the
Paleozoic. This marine fauna is known as the
'Cambrian Fauna' and represents the first great
marine faunal assemblage in the fossil record.
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- The Cambrian Fauna and Beyond
This fauna was replaced by the 'Paleozoic' ( or
Brachiopod) fauna, and then by the Modern (or
'Gastropod-Mollusc') fauna in the Mesozoic.
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- The Cambrian Fauna and Beyond - What
contributes to these patterns in diversity?
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- The Cambrian Fauna and Beyond - What
contributes to these patterns in diversity?
Some paleontologists suggest a correlation
between large scale diversity patterns and plate
tectonics.
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- The Cambrian Fauna and Beyond - What
contributes to these patterns in diversity?
Some paleontologists suggest a correlation
between large scale diversity patterns and plate
tectonics. This is the supercontinent "Rodinia".
It formed about 1 billion years ago, and began
to break up in the Cambrian (544-510) and
Ordovician (510-439).
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- The Cambrian Fauna and Beyond - What
contributes to these patterns in diversity?
So, we have 'vicariance' at a large geologic
scale, increase the abundance of shallow coastal
habitats and the possibility of allopatric
speciation, divergence, and radiations.
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A similar radiation in diversity occurs in the
Mesozoic when Pagaea breaks up... creating more
shallow coastal areas...
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- The Cambrian Fauna and Beyond - What
contributes to these patterns in diversity?
1) Vicariance 2) Nutrient Loading
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- The Cambrian Fauna and Beyond - What
contributes to these patterns in diversity?
1) Vicariance 2) Nutrient Loading
increase in shallow seas increases marine
productivity and might increase food chain
lengths and diversity. also, evolution of more
productive terrestrial biotas would increase
nutrient contributions from runoff.
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- The Cambrian Fauna and Beyond - What
contributes to these patterns in diversity?
1) Vicariance 2) Nutrient Loading 3) Mass
Extinctions
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Impact, Climate
Ice Age
Vulcanism
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I. The Precambrian - Vendian II. Paleozoic
A. Cambrian (544-510 mya)
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I. The Precambrian - Vendian II. Paleozoic
A. Cambrian (544-510 mya) - evolution of
chordates
Pikaia
Cephalochordata
Euchordata
Hagfish (skull but no vertebrae...)
Myllokunmingia 530 mya
Haikouichthys 530 mya
Craniata
Vertebrata
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I. The Precambrian - Vendian II. Paleozoic
A. Cambrian (544-510 mya) - evolution of
chordates
Myllokunmingia 530 mya Nature 1999
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Haikouichthys ercaicunensis early
Cambrian perhaps more advanced than
Myllokunmingia, but both may have had
cartilaginous vertebrae... the first true
verts! Nature 2003

Myllokunmingia 530 mya
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I. The Precambrian - Vendian II. Paleozoic
A. Cambrian (544-510 mya) B. Ordovician
(510-439 mya)
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I. The Precambrian - Vendian II. Paleozoic
A. Cambrian (544-510 mya) B. Ordovician
(510-439 mya)
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I. The Precambrian - Vendian II. Paleozoic
A. Cambrian (544-510 mya) B. Ordovician
(510-439 mya)
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I. The Precambrian - Vendian II. Paleozoic
A. Cambrian (544-510 mya) B. Ordovician
(510-439 mya) - inverts new trilobites
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I. The Precambrian - Vendian II. Paleozoic
A. Cambrian (544-510 mya) B. Ordovician
(510-439 mya) - inverts new trilobites Nautil
oid radiation
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During the middle Ordovician some long-shelled
forms like Endoceras and Cameroceras attained
lengths of 4 to as much as 10 meters - among the
largest molluscan shells ever

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I. The Precambrian - Vendian II. Paleozoic
A. Cambrian (544-510 mya) B. Ordovician
(510-439 mya) Radiation of Ostracoderms SILURIAN
Lampreys
Heterostracans
Astraspids
"Ostracoderms"
Arandaspids
Osteostracans
Tree of Life phylogeny differs from Cowens.
JAWED FISHES
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"Ostracoderms" Bony plates no paired fins gill
arches
I. The Precambrian - Vendian II. Paleozoic
A. Cambrian (544-510 mya) B. Ordovician
(510-439 mya)
Astraspis
Arandaspida
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I. The Precambrian - Vendian II. Paleozoic
A. Cambrian (544-510 mya) B. Ordovician
(510-439 mya) - plants the first terrestrial
plant fossils are fragmentary they are spores
and cuticles (which signify land plants). In all
likelihood they are 'hepatophyte' liverwort-like
non-tracheophytes...
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I. The Precambrian - Vendian II. Paleozoic
A. Cambrian (544-490 mya) B. Ordovician
(490-443 mya) C. Silurian (443-417 mya) -
inverts Brachipods begin to dominate 80 of
all individuals
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C. Silurian (443-417 mya) - inverts Brachipods
begin to dominate 80 of all individuals Reef-
building corals radiate
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C. Silurian (443-417 mya) - inverts Brachipods
begin to dominate 80 of all individuals Reef-
building corals radiate Crinoid echinoderms
radiate
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C. Silurian (443-417 mya) - inverts Brachipods
begin to dominate 80 of all individuals Reef-
building corals radiate Crinoid echinoderms
radiate Eurypterids (sea scorpions) dominate (7
feet long)
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C. Silurian (443-417 mya) - inverts Brachipods
begin to dominate 80 of all individuals Reef-
building corals radiate Crinoid echinoderms
radiate Eurypterids (sea scorpions) dominate
Horseshoe crabs Semi-aquatic scorpions and
terrestrial Chelicerata evolve Millipedes first
completely terrestrial animals
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C. Silurian (443-417 mya) - inverts - plants
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C. Silurian (443-417 mya) - inverts -
plants radiation of the first vascular
plants 4 species of Cooksonia, including those
representing the Rhyniophytes and Lycophytes
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C. Silurian (443-417 mya) - inverts -
plants - verts
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C. Silurian (443-417 mya) - inverts -
plants - verts Radiation of
Ostracoderms SILURIAN
Lampreys
Heterostracans
Astraspids
"Ostracoderms"
Arandaspids
Osteostracans
Tree of Life phylogeny differs from Cowens.
JAWED FISHES
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C. Silurian (443-417 mya) - inverts -
plants - verts - Heterostracans - over 300
species very abundant
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C. Silurian (443-417 mya) - inverts -
plants - verts - Osteostracans
bottom-feeders, but with an important
evolutionary advancement - paired fins
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C. Silurian (443-417 mya) - inverts -
plants - verts - Jawed Fishes
(Gnathostomes) - Acanthodians
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C. Silurian (443-417 mya) - inverts -
plants - verts - Jawed Fishes
(Gnathostomes) the oldest jawed fish fossils are
Acanthodians... however, they are a group of bony
fishes and it is likely that they were preceded
by the cartilaginous Placoderms (which radiate in
the Devonian)
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I. The Precambrian - Vendian II. Paleozoic
A. Cambrian (544-490 mya) B. Ordovician
(490-443 mya) C. Silurian (443-417 mya)
D. Devonian (417-354 mya) - "The Age of Fishes"
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D. Devonian (417-354 mya) - inverts
crazy trilobite 50cm long.... Terataspis grandis
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D. Devonian (417-354 mya) - inverts -
Ammonites
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D. Devonian (417-354 mya) - inverts -
Ammonites - Terrestrial Arthropods -
oldest spider - Attercopus - mites -
trigonotarbids (no silk)
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D. Devonian (417-354 mya) - inverts -
plants Lycopod forests, then
Progymnosperm forests dominated by one genus,
Archaeopteris 20m
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D. Devonian (417-354 mya) - inverts -
plants - verts - last of the ostracoderms...
Psammolepis over 2m
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D. Devonian (417-354 mya) - inverts -
plants - verts - last of the
ostracoderms... - the major radiation of jawed
fish groups
Arthrodires
Placoderms
Antiarchs
Chondrichthyes (Sharks, rays)
Acanthodians
Teleosts
Ray-finned Fishes
Bony Fish
Lobe-finned Fishes
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D. Devonian (417-354 mya)
Fishes of  the Middle Devonian locality of Lethen
Bar, in Scotland (Givetian, about 377 Ma). They
include antiarchs (1 Pterichthyodes) and
arthrodire (2. Coccosteus) placoderms,
acanthodians (3. Diplacanthus), ray-finned fish
(4, Cheirolepis), lungfish  (5, Dipterus), and
osteolepiform lobe-finned fish (6. Osteolepis),
representing the lineage that gave rise to land
animals.
109

D. Devonian (417-354 mya) - Placoderms -
Sharks - Lobe-finned Fishes - Ray-finned
Fishes - Tetrapods (from lobe-finned fishes)
110
D. Devonian (417-354 mya) - Placoderms -
very abundant - head shields - shearing or
crushing tooth plates
Dunkleosteus - 6m
Arthrodire
Antiarch
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D. Devonian (417-354 mya) - Placoderms -
Sharks
Stethacanthus - 2m
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D. Devonian (417-354 mya) - Placoderms -
Sharks
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D. Devonian (417-354 mya) - Placoderms -
Sharks - Ray-finned Fishes
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D. Devonian (417-354 mya) - Placoderms -
Sharks - Ray-finned Fishes
115
D. Devonian (417-354 mya) - Placoderms -
Sharks - Ray-finned Fishes - Lobe-finned
Fishes
116
D. Devonian (417-354 mya) - Placoderms -
Sharks - Lobe-finned Fishes
365 mya
385 mya
117

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Eusthenopteron

119
Panderichthys rhombolepis

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Tiktaalik roseae

121
Acanthostega gunnari

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Ichthyostega sp.

123
I. The Precambrian - Vendian II. Paleozoic
A. Cambrian (544-490 mya) B. Ordovician
(490-443 mya) C. Silurian (443-417 mya)
D. Devonian (417-354 mya) E. Carboniferous
(359-300 mya)
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E. Carboniferous (359-300 mya) - inverts
Arthropleura -largest terrestrial arthropod - 2m
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E. Carboniferous (359-300 mya) - inverts
- radiation of insects - evolution of flight
Meganeura monyi - largest insect ever wingspan of
70 cm
126
E. Carboniferous (359-300 mya) - inverts -
plants
The early Carboniferous saw a reduction in the
Devonian forests and a dominance of small plants
- lycopods and their kin. Lepidodendron Psaronius
- fern Lebachia - progymnosperm Cordaites -
progymnosperm
127
E. Carboniferous (359-300 mya) - inverts -
plants
The early Carboniferous saw a reduction in the
Devonian forests and a dominance of small plants
- lycopods and their kin. As the period
proceeds, the giant lycopsid swamp forests evolve
across the tropical continent of Euramerica.
There was lots of photosynthesis, but this was
not balanced by decomposition (because much of
the biomass was preserved in sediment, not broken
down by decay). So, oxygen production by
photosynthesis exceeded oxygen consumption by
decomposition... and oxygen levels were probably
very high...this may have allowed the enormous
size of invertebrates.
128
E. Carboniferous (359-300 mya) - inverts -
plants
129
E. Carboniferous (359-300 mya) - inverts -
plants
Coal deposits in shallow tropical swamps
130
E. Carboniferous (359-300 mya) - inverts -
plants - vertebrates sharks replace
placoderms as dominant in oceans

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The golden age of sharks - 45 Families (currently
21)
132
E. Carboniferous (359-300 mya) - inverts -
plants - vertebrates sharks replace
placoderms as dominant in oceans ray finned
fishes dominate in fresh water

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- vertebrates radiation of stem tetrapods!!

134
- vertebrates radiation of stem tetrapods!!

135
- vertebrates radiation of stem tetrapods!!

"Anthracosaurs"
136
E. Carboniferous (359-300 mya) - inverts -
plants - vertebrates sharks replace
placoderms as dominant in oceans ray finned
fishes dominate in fresh water stem tetrapods
radiate!

"crown" tetrapods
Seymouriamorpha
Temnospondyls
Ichthyostegans
137
E. Carboniferous (359-300 mya) - inverts -
plants - vertebrates stem tetrapods

Temnospondyls a very diverse radiation of
tetrapods, from alligator-like salamanders to
large, scaled, frog-like creatures. Cowens
places these ancestral to Amphibia only, but
recent analyses put them as a sister clade to all
crown tetrapods.
138
Temnospondyls a very diverse radiation of
tetrapods, from alligator-like salamanders to
large, scaled, frog-like creatures. Cowens
places these ancestral to Amphibia only, but
recent analyses put them as a sister clade to all
crown tetrapods.


139
Seymouriamorpha


Radiate in Permian but earliest fossils from the
Carboniferous... larvae have external gills,
which pulls them out of the amniota...
140
- vertebrates radiation of stem tetrapods!!

141
The Amniote Divide


The amniotic egg was a big advance - amnion
protects the embryo - yolk sac provides
nourishment - allantoic sac holds waste produced
by embryo
Resist desiccation Provision embryo allows for
colonization of dry habitats
142
Primitive Amniotes Hylonomus lyelli an early
reptile Carboniferous of Nova Scotia


143
E. Carboniferous
- The Amniote Radiations
SYNAPSID
Anapsid ancestor Hylonomus Casineria
ANAPSID (turtles?)
DIAPSID
144
I. The Precambrian - Vendian II. Paleozoic
A. Cambrian (544-490 mya) B. Ordovician
(490-443 mya) C. Silurian (443-417 mya)
D. Devonian (417-354 mya) E. Carboniferous
(359-300 mya) F. Permian (300-251 mya)
145
F. Permian (300-251 mya)
Pangaea forms
The fusion of land masses reduced the amount of
humid coastline and increased the extent of dry
inland areas. This favored the amniote
radiations over "amphibian" clades.
146
F. Permian
- The Amniote Radiations Diversify
SYNAPSID
Anapsid ancestor Hylonomus
ANAPSID (turtles)
DIAPSID
147
F. Permian (300-251 mya)
Synapsids dominate through the early Permian
Pelycosaurs
Dicynodonts
Gorgonopsids
Therapsids
Cynodonts
Mammals
148
F. Permian (300-251 mya)
Pelycosaurs dominate early
include the great sail-finned animals like
Dimetrodon
149
F. Permian (300-251 mya)
Early Therapsids, like Gorgonopsids, dominate in
the mid-late Permian
Moschops
Dinocephalians
150
F. Permian (300-251 mya)
Dicynodonts come to numerical dominance in the
late Permian
abundant herbivores
151
F. Permian (300-251 mya)
and the first Cynodonts appear
152
F. Permian (300-251 mya)
large herbivorous anapsids were also present
153
F. Permian (300-251 mya)
Diapsids were small and lizard-like the
Synapsids ruled terrestrial communities
154
F. Permian (300-251 mya)
- Plants!!
155
F. Permian (300-251 mya)
- Plants!! - the dry climate reduced the
great Carboniferous swamp forests lycopods
shrink... - Ferns, and gymnosperms ("seed
ferns", Ginkos, Cycads, and Conifers) gain
prominence... - In particular Glossopteris - a
seed fern - that produces seeds on its leaves
like sori of ferns...
The evolution of gymnosperms introduced two
important adaptive features - pollen (male
gametophyte) - no more swimming sperm reduced
reliance on open water habitats - seed -
protective seed coat reduced desiccation of
embryo, and nutritious endosperm provisioned the
embryo with energy. (Like the amniote egg).
156
F. Permian (300-251 mya)
The great Permian extinction!!!!
A huge mantle plume rises towards the surface...
157
F. Permian (300-251 mya)
The great Permian extinction!!!!
then it pops like a zit!!
158
F. Permian (300-251 mya)
The great Permian extinction!!!!
A huge mantle plume rises towards the
surface... resulting in a great bubble of flowing
lava... the Siberian flats (200,000 squ. mi)
159
F. Permian (300-251 mya)
160
F. Permian (300-251 mya) -
results 90-95 of marine species go
extinct... trilobites placoderms acanthodian
s
161
F. Permian (300-251 mya) -
results 90-95 of marine species go
extinct... trilobites placoderms acanthodian
s 70 of all land families pelycosaurs