Vertebrates

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Vertebrates

• Chapter 34

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The Animal Kingdom
35 phyla
gt95 inverts.
lt5 verts.
Fig. 32.11Table 33.7
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Human embryo (5 weeks)
Deuterostomia
P. Chordata
Notochord attachment site for muscles
Lancelet (adult)
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Human embryo (5 weeks)
Deuterostomia
P. Chordata
Notochord attachment site for muscles
Lancelet (adult)
Dorsal, hollow nerve cord one end forms the
brain (if present)
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Human embryo (5 weeks)
Deuterostomia
P. Chordata
Notochord attachment site for muscles
Lancelet (adult)
Pharyngeal gill slits
Dorsal, hollow nerve cord one end forms the
brain (if present)
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Human embryo (5 weeks)
Deuterostomia
P. Chordata
Notochord attachment site for muscles
Lancelet (adult)
Pharyngeal gill slits
Dorsal, hollow nerve cord one end forms the
brain (if present)
Postanal tail
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P. Chordata
Deuterostomia
Invertebrate subphyla
Urochordata
Cephalochordata
Fig. 34.2
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P. Chordata
Subphylum Urochordata
Tunicates a.k.a. sea squirts
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P. Chordata
Subphylum Urochordata
Tunicates a.k.a. sea squirts
The key shared derived characters of chordates
are found in the larval stage
adults
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P. Chordata
Subphylum Cephalochordata
Lancelets
The key shared derived characters of chordates
are found in the adult stage
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P. Chordata
Deuterostomia
Craniates
A key shared derived character neural crest,
which gives rise developmentally to cartilage or
bones of the skull
Hagfishes
Vertebrates
Fig. 34.2
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P. Chordata
Class hagfishes
Cartilaginous skull and notochord
No vertebrae
No jaws
No paired appendages
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P. Chordata
Deuterostomia
Vertebrates
A key shared derived character vertebrae
Lampreys
Gnathostomes
Fig. 34.2
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P. Chordata
Class lampreys
Cartilaginous skeleton, including a structure
surrounding the notochord with rudimentary
vertebrae
No jaws
No paired appendages
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P. Chordata
Deuterostomia
Gnathostomes
Key shared derived characters hinged jaws and
mineralization of skeleton
Chondrichthyes
Osteichthyans
Fig. 34.2
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P. Chordata
Class Chondrichthyes
Over 750 species of sharks, skates, rays
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P. Chordata
Class Chondrichthyes
and ratfish, or chimaeras
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P. Chordata
Class Chondrichthyes
Notochord present only in embryos
Predominantly cartilaginous skeleton
Respire through gills
Lateral line system for detecting pressure changes
2-chambered heart
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P. Chordata
Class Chondrichthyes
Oviparous embryonic development fueled from
nutrients supplied by yolk, and the unshelled
eggs hatch outside the mothers body
Ovoviviparous embryonic development fueled by
yolk, but the eggs hatch inside the mothers body
Viviparous embryonic development fueled by
mothers blood through a placenta live birth
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P. Chordata
Deuterostomia
Osteichthyans
Key shared derived character ossified skeleton
(hard matrix of calcium phosphate)
Ray-finned fishes
Lobe-fins
Fig. 34.2
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P. Chordata
Class ray-finned fishes
Very diverse group over 30,000 extant species
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P. Chordata
Class ray-finned fishes
Notochord present only in embryos
Ossified (bony) skeleton
Respire through gills
Lateral line system for detecting pressure changes
2-chambered heart
Swim bladder air-filled sac that helps control
buoyancy
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P. Chordata
Deuterostomia
Lobe-fins
Key shared derived character rod-shaped bones
in fins or limbs
Coelacanths
Lungfishes
Tetrapods
Fig. 34.2
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P. Chordata
Class coelacanths
coelocanth
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P. Chordata
Class lungfishes
Respiration through gills supplemented by lungs
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P. Chordata
Deuterostomia
Tetrapods
Key shared derived character limbs in place of
pectoral and pelvic fins
Amphibia
Amniotes
Fig. 34.2
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P. Chordata
Class Amphibia
Two lives
Larvae generally aquatic, adults generally
terrestrial
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P. Chordata
Bony skeleton
3-chambered heart
Class Amphibia
Generally respire through lungs as adults,
supplemented by gas exchange through the skin
Two lives
Larvae generally aquatic, adults generally
terrestrial
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P. Chordata
Class Amphibia
Two lives
External fertilization is common
Eggs lack a shell and are prone to desiccation
Over 4,800 extant species
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P. Chordata
Class Amphibia
Order Anura (tail-less ones) frogs, toads
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P. Chordata
Class Amphibia
Order Urodela (tailed ones) salamanders, newts
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P. Chordata
Class Amphibia
Order Apoda (legless ones) caecilians
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P. Chordata
Deuterostomia
Amniotes
Key shared derived character amniotic egg,
which contains specialized extraembryonic
membranes
Reptilia
Mammalia
Fig. 34.2
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Deuterostomia
P. Chordata
Amniotes
Key shared derived character amniotic egg,
which contains specialized extraembryonic
membranes
Reptilia
Mammalia
Fig. 34.23
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Extraembryonic membranes (and a shell in many
species) are not part of the embryos body, and
aid gas exchange, waste storage, and nutrition
Fig. 34.24
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P. Chordata
Reptilia
About 6,500 extant species (excluding birds)
Leathery shell around egg
3-chambered heart (4 in crocodilians)
Scales
Ectothermic
Internal fertilization
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P. Chordata
Reptilia
E.g., turtles, tortoises
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P. Chordata
Reptilia
E.g., squamates (snakes and lizards)
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P. Chordata
Reptilia
E.g., crocodilians
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P. Chordata
Birds
About 8,600 extant species, in about 28 orders
Eggs with hard shells (calcium carbonate)
Feathers highly modified scales
Endothermic
4-chambered heart
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P. Chordata
Birds
Clear genetic, morphological, and fossil evidence
for phylogenetic nesting within Reptilia
Archaeopteryx
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Cassowary
P. Chordata
Class Aves
Some groups lost the ability to fly
Penguins
Emu
Kiwi
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Deuterostomia
P. Chordata
For Reptilia to be monophyletic, it must contain
the birds
Fig. 34.23
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Deuterostomia
P. Chordata
Now lets consider the mammals
Fig. 34.23
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P. Chordata
Mammalia
About 4,500 extant species in about 16 orders
Hair
Endothermic
4-chambered heart
Mammary glands
Differentiated, specialized teeth
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P. Chordata
Monotremes
Mammalia
Egg-laying mammals
Fig. 34.36
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P. Chordata
Monotremes
Mammalia
Platypus
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P. Chordata
Monotremes
Mammalia
Echidna
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P. Chordata
Marsupials
Mammalia
Embryonic development occurs outside the mother,
often in a marsupium
Fig. 34.36
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P. Chordata
Marsupials
Mammalia
Embryonic development occurs outside the mother,
often in a marsupium
At birth
After 17weeks in pouch
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P. Chordata
Marsupials
Mammalia
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P. Chordata
Eutherians (Placental Mammals)
Mammalia
Embryonic development occurs inside the mothers
uterus, joined by the placenta
African origin radiation
S. American radiation
Fig. 34.36
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P. Chordata
Eutherians (Placental Mammals)
Mammalia
Embryonic development occurs inside the mothers
uterus, joined by the placenta
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P. Chordata
Eutherians (Placental Mammals)
Mammalia
Carnivores, herbivores, etc.
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P. Chordata
Eutherians (Placental Mammals)
Mammalia
Terrestrial, freshwater, marine
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P. Chordata
Eutherians (Placental Mammals)
Mammalia
Some are even volant!
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P. Chordata
A special group (from our human perspective)
Mammalia, Order Primates
0
Chim-panzees
Humans
Gorillas
Tarsiers
Gibbons
Orangutans
Old World monkeys
New World monkeys
Lemurs, lorises, and pottos
Millions of years ago
Fig. 34.38
Ancestral primate
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P. Chordata
Mammalia, Order Primates
Humans
0
Opposable thumbs
Chim-panzees
Humans
Gorillas
Tarsiers
Gibbons
Orangutans
Old World monkeys
New World monkeys
Lemurs, lorises, and pottos
Highly developed cerebral cortex
Millions of years ago
Fig. 34.38
Ancestral primate