CHORDATES

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CHORDATES
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SPONGES CAN FIGHTPLASTIC DUCKS
!!!
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S C F P D
Ribosomal RNA tree
time
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S C F D P
Ribosomal RNA tree
time
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DEUTEROSTOMES
Three tissue layers, bilateral symmetry, radial
cleavage, mouth secondary
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BLASTOPORE
A M M
A
Protostome Deuterostome
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CHORDATECLEAVAGE
RADIAL Deuterostomes
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CHORDATES
gt 56, 000 species (half are fish) Incredible
diversity of lifestyles All habitats mainly
aquatic
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Theme 1
What is the evidence that Chordates Echinoderms
are sister phyla?
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Theme 2
Chordate characters were excellent adaptations
to a free-living life in the sea
(Moore
2006) What were these characters? How did
they influence chordates success in non-marine
habitats?
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Smallest chordate 2 mm long
Individuals in tunicate colony
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Largest 35 metres long
Blue Whale
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CHORDATEBAUPLAN

• Bilaterally symmetric triploblasts

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TRIPLOBLASTS
Three tissue layers
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COELOM
HOLE IN MESODERM
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COELOM
Coelom Gut
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ORIGIN OFMESODERM
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ORIGIN OFCOELOM
gut
Coelom derived from gut
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CHORDATEBAUPLAN
Anus

• Bilaterally symmetric triploblasts
• Post-anal tail

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CHORDATEBAUPLAN

• Bilaterally symmetric triploblasts
• Post-anal tail
• Pharyngeal slits often used as gills

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CHORDATEBAUPLAN

• Bilaterally symmetric triploblasts
• Post-anal tail
• Pharyngeal slits
• Hollow dorsal nerve cord

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CHORDATEBAUPLAN

• Bilaterally symmetric triploblasts
• Post-anal tail
• Pharyngeal slits
• Hollow dorsal nerve cord
• Notochord stiff jelly-like rod

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CHORDATE BAUPLAN
ana
Notochord
Hollow nerve cord
Post-anal tail
Pharyngeal slits
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PHYLUM SPLIT INTO3 GROUPS
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Tunicates Lancelets Vertebrates
Ribosomal RNA tree
time
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CHORDATEGROUP 1
SEA SQUIRTS
Sessile filter-feeders
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SEA SQUIRTS TUNICATES
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LARVAmobilefilter feeder
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(No Transcript)
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CHORDATEGROUP 2
LANCELETS
Burrowing filter-feeders
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LANCELETS
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CHORDATEGROUP 3
VERTEBRATES
Bone
Mobile diverse
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(No Transcript)
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Largest 35 metres long
Blue Whale
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Smallest vertebrate 8.4 mm long
Stout Infantfish
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VERTEBRATES VIEWED BY US
Mammals
Birds Reptiles Amphibians Fish
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FOUR VERTEBRATE GRADES
Mammals
Birds Reptiles Amphibians Fish
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FISH TETRAPODS
Mammals
Birds Reptiles Amphibians Fish
4 Limbs
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FISH, AMPHIBIANS AMNIOTES
Amniote egg
Mammals
Birds Reptiles Amphibians Fish
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FISH, AMPHIBIANS, REPTILES HOMEOTHERMS
Homeothermy
Mammals
Birds Reptiles Amphibians Fish
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TWO VERTEBRATE CLADES
Mammals
Birds Reptiles Amphibians Fish
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VERTEBRATES VIEWED BY MARTIAN
Ray-finned Fish Lobe-finned Fish
TETRAPODS