III.%20Mesozoic%20Era

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III. Mesozoic Era A. Triassic Period (250 - 205
mya)
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) - climate Dry low sea levels one
large supercontinent beginning to break up
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) - inverts - marine communities -
gastropods and molluscs begin to dominate in
these initially depauperate faunas... the 'modern
marine fauna', including modern reef-builders
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) - Plants - recovery from the mass
extinction is slow lycopsids dominate
early, but soil formation is very slow... -
dry climate selects for seed plants with
pollen the Gymnosperms...
Petrified Forest N. P.
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) - Verts - Medium sized therapsids
dominate early... like Lystrosaurus
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Triassic survivors
Pelycosaurs
Dicynodonts
Gorgonopsids
Therapsids
Cynodonts
Mammals
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) - Verts - Medium sized therapsids
dominate early... like Lystrosaurus -
Temnospondyls resurgent (Mastodonosaurus - 6m)
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) - Verts - radiation of the diapsids,
but only Ichthyosaurs abundant early
Archosaurs Dinosaurs, Pterosaurs, Crocodilians,
Birds
Lepidosaurs Lizards, Snakes, Sphenodonts,
Plesiosaurs)
Diapsida
Ichthyosaurs
Younginiformes
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) - Verts - the opening of the shallow
Tethys Sea between Laurasia and Gondwanaland
created a very productive marine environment,
which was exploited by a diverse group of
evolving marine reptiles in the three major
diapsid groups
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Archeosaurs Tanystropheus
III. Mesozoic Era A. Triassic Period (250 - 205
mya) - Verts - marine reptiles
Ichthyosaurs
Lepidosaurs Nothosaurus
Placodonts
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) - Verts - marine reptiles
Shonisaurus - 21m
(Blue Whale 33m, 110 ft)
Lepidosaurs Nothosaurus
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) - Verts - As the Triassic proceeds,
the Archosaurs displace the Therapsids.
crucrotarsi
Crocodylomorphs (Ornithosuchans and Phytosaurs)
Pterosaurs
Ornithodira (Marasuchas)
Dinosaurs
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) - Verts - As the Triassic proceeds,
the Archosaurs displace the Therapsids. -
Crocodylomorphs
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) - Verts - As the Triassic proceeds,
the Archosaurs displace the Therapsids. - In
the late Triassic, the first Dinosaur radiations
occur.
Ornithichians
Prosauropods
Saurichians
Sauropods
Theropods
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) - Verts - As the Triassic proceeds,
the Archosaurs displace the Therapsids. - In
the late Triassic, the first Dinosaur radiations
occur.
Ornithischians
Ornithichians
Prosauropods
Sauropods
Theropods
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) - Verts - As the Triassic proceeds,
the Archosaurs displace the Therapsids. - In
the late Triassic, the first Dinosaur radiations
occur.
Saurischians
Ornithichians
Prosauropods
Sauropods
Theropods
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) - Verts - As the Triassic proceeds,
the Archosaurs displace the Therapsids. - In
the late Triassic, the first Dinosaur radiations
occur. Oldest Dinosaurs are the Theropod-like
Eoraptor
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) - Verts - As the Triassic proceeds,
the Archosaurs displace the Therapsids. - In
the late Triassic, the first Dinosaur radiations
occur. The first radiation of large dinosaurs
were the herbivorous Prosauropods
By the late Triassic, all large herbivores were
Sauropodomorphs.
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) - Verts - the first mammaliforms...
Morganucodontids
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III. Mesozoic Era B. Jurassic (200-146 mya) -
Climate A global greenhouse - lush tropical
habitats and rich shallow seas lead to the period
of maximum Dinosaur domination.
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III. Mesozoic Era B. Jurassic (200-146 mya) -
Marine Reptiles Ichthyosaurs still present...
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III. Mesozoic Era B. Jurassic (200-146 mya) -
Marine Reptiles but now joined by Plesiosaurs
and Pliosaurs (both Lepidosaurs)
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III. Mesozoic Era B. Jurassic (200-146 mya) -
Marine Reptiles and marine crocodylians....
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III. Mesozoic Era B. Jurassic (200-146 mya) -
Herbivores Ornithichian Stegosaurs
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III. Mesozoic Era B. Jurassic (200-146 mya) -
Herbivores Sauropods - the first of the real
giants
1, small head and peg-like teeth (and elongated
cervical vertebrae) 2, addition of extra
cervical vertebrae to the neck 3, apron-like
pubis 4, fore limbs as long as or longer than
hind limbs, making the back slope posteriorly 5,
teeth restricted to front of mouth 6,
armor.
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III. Mesozoic Era B. Jurassic (200-146 mya) -
Herbivores Sauropods - the first of the real
giants Ultrasaurus (maybe a Brachiosaurus) stood
98 ft long, 140 tons
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III. Mesozoic Era B. Jurassic (200-146 mya) -
Herbivores Sauropods - the first of the real
giants Diplodocus - 90 ft long 11 tons
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III. Mesozoic Era B. Jurassic (200-146 mya) -
Carnivores
1. three-toed foot2. digits IV and V lost on
hand3. long arms4. semilunate carpal5. fused
pelvis6. large hole in lacrimal bone in skull7.
?no unique derived characters?8. giant,
hook-like claw on digit II of pes9. flight
feathers
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III. Mesozoic Era B. Jurassic (200-146 mya) -
Carnivores - Ceratosaurs
Ceratosaurus
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III. Mesozoic Era B. Jurassic (200-146 mya) -
Carnivores - Carnosaurs
Allosaurus
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III. Mesozoic Era B. Jurassic (200-146 mya) -
Carnivores - Avialae
Archaeopteryx
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III. Mesozoic Era B. Jurassic (200-146 mya) -
Carnivores - Avialae
Archaeopteryx
First fossil - 1860 - a flight feather
(asymmetrical)
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The 'London' Specimen - 1861
The 'Berlin' Specimen - 1877
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10th specimen described in 2005 - shows
intermediately rotated halux
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10th specimen described in 2005 - shows
intermediately rotated halux and hyperextended
2nd digit (like Deinonychosaurs - their sister
clade)
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10th specimen described in 2005 - shows
intermediately rotated halux and hyperextended
2nd digit (like Deinonychosaurs - their sister
clade)
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Hand Morphology
A. Herrerasaurus- five digits are present, Digit
V shaded yellow and hidden on other side of hand.
B. Coelophysis. Note that digit V is gone.
C. Deinonychus. Note loss of both digits V and
IV D. Archaeopteryx. Note very close
correspondence in proportions and relative
lengths of bones to Deinonychus. E. Hoatzin
embryo. Number of bones reduced in digit III. F.
Hoatzin adult. Most of the bones of the hand
fused
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Another Set of Examples
Ornitholestes (theropod dinosaur)
Archaeopteryx
Archaeopteryx
Sinornis (a Cretaceous bird)
Modern chicken
Chicken
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III. Mesozoic Era B. Jurassic (200-146 mya) -
Pterosaurs They were present in the Triassic,
but reached their greatest diversity in the
Jurassic, with over 80 species recorded.
However, they would attain their greatest size in
the Cretaceous.
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III. Mesozoic Era B. Jurassic (200-146 mya) -
Pterosaurs They were present in the Triassic,
but reached their greatest diversity in the
Jurassic, with over 80 species recorded.
However, they would attain their greatest size in
the Cretaceous.
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III. Mesozoic Era B. Jurassic (200-146 mya) -
Mammals Docodonts.... a group of beaver-like
animals... the most impressive fossil of the
group was found in Feb 2006 - oldest animal
with fur - demonstrates that mammals were
radiating into a variety of habitats
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) B. Jurassic (205 - 146 mya) C. Cretaceous
(145 - 65 mya)
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) B. Jurassic (205 - 146 mya) C. Cretaceous
(146 - 65 mya) - the warming trend of the
Jurassic continues, and results in very high sea
levels and the expanse of shallow seas over
significant portions of continents
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) B. Jurassic (205 - 146 mya) C. Cretaceous
(146 - 65 mya) - Plants Evolution of
Angiosperms Initially in low
abundance Come to dominate by end of
Cretaceous
Gymnosperms
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) B. Jurassic (205 - 146 mya) C. Cretaceous
(146 - 65 mya) - Plants Evolution of
Angiosperms Initially in low
abundance Come to dominate by end of
Cretaceous
Gymnosperms
Angiosperms
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Archaefructus sinensis Science 2002
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) B. Jurassic (205 - 146 mya) C. Cretaceous
(146 - 65 mya) - Plants Evolution of
Angiosperms Initially in low
abundance Come to dominate by end of
Cretaceous
Gymnosperms
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) B. Jurassic (205 - 146 mya) C. Cretaceous
(146 - 65 mya) - Plants Evolution of
Angiosperms Initially in low
abundance Come to dominate by end of
Cretaceous
Gymnosperms
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III. Mesozoic Era A. Triassic Period (250 - 205
mya) B. Jurassic (205 - 146 mya) C. Cretaceous
(146 - 65 mya) - Inverts radiation of
pollinators radiation of pollinators and
herbivores ground beetles do not
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C. Cretaceous - Verts -Crocodylians
Sarcosuchus 11m
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C. Cretaceous (146 - 65 mya) - Inverts -
Verts Ornithischians Stegosaurs give
way to a variety of new Ornithischian
groups
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Ornithischians Ankylosaurs
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Ornithischians Ceratopsians
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Ornithischians Iguanodonts
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Ornithischians Hadrosaurs
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Ornithischians Pachycephalosaurs
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C. Cretaceous (146 - 65 mya) - Inverts -
Verts Ornithischians Saurischians
- Sauropods The Titanosaurs (and they were
still big)
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The Titanosaurs Andesaurus 40m (?) 80 tons
(?) incomplete skeleton
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The Titanosaurs Argentinasaurus Largest one
known with confidence, but there are bigger
single bones.... 35m 80-100 tons incomplete
skeleton but a hip girdle, vertebrae, and tibia

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C. Cretaceous - Theropods carnivores get
big!! Carnosaurs - Giant Allosaur cousins
like Giganotosaurus
Longer than the largest Tyrannosaurus rex by
2m 40-45 ft... from Argentina (1995)
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C. Cretaceous Carnosaurs - Giant Allosaur
cousins like Carcharodontosaurus
40 ft - slightly smaller than T. rex from Niger
(1927)
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C. Cretaceous Carnosaurs - Tyrannosaurs -
Albertosaurus
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C. Cretaceous Carnosaurs - Tyrannosaurs -
Gorgosaurus
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C. Cretaceous Carnosaurs - Tyrannosaurs -
Tyrannosaurus (3 sp.)
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C. Cretaceous Carnosaurs - Tyrannosaurs -
Tyrannosaurus (3 sp.)
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C. Cretaceous Carnosaurs - Tyrannosaurs -
Tyrannosaurus (3 sp.)
Soft tissue from a femur? Yup!
http//www.livescience.com/41537-t-rex-soft-tissue
.html
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C. Cretaceous Carnosaurs - Tyrannosaurs -
Dilong paradoxicus Feathered
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C. Cretaceous Carnosaurs - Tyrannosaurs -
Spinosaurs - Spinosaurus largest land
carnivore? 40-60 ft?
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C. Cretaceous - Deinonychians Deinonychus V
elaciraptor
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III. Mesozoic C. Cretaceous - theropods
(still) - Deinonychians Velociraptor
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C. Cretaceous - non-bird feathered
dinosaurs Sinosauropteryx prima (1996) first
non-bird dinosaur with feathers... a Cretaceous
contemporary of birds
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- Protobirds
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- Protobirds Sinornithosaurus (Jurassic)
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- Protobirds Microraptor (Cretaceous)
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Protobirds - Deinonychians Velociraptor
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- Protobirds Unenlagia (Cretaceous)
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- Protobirds Caudipterxy (Cretaceous)
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- Protobirds Protarchaeopteryx (Cretaceous)
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- Protobirds Eoalulavis (Cretaceous)
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- Pterosaurs
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- Pterosaurs Pteranodon - wingspan 7.5 m
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- Pterosaurs
Quetzalcoatlus - largest ptersaur 40 ft
wingspan....
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- Quetzalcoatlus - largest flying animal
Quetzalcoatlus - largest ptersaur 40 ft
wingspan....
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- Mammals...
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- Mammals... - Multituberculates Dominate in
Cretaceous - over 200 species
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The K-T Boundary
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The K-T Boundary
hmm... a new star in the constellation of
Orion... THAT'S weird...
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The K-T Boundary
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The K-T Boundary
WHAT THE HELL!!!
It's the Ceratopsians... they're attacking...!!!
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The K-T Boundary
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The K-T Boundary
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The K-T Boundary
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The K-T Boundary