A. Infraorder Tetanurae. Orbit is higher & smaller than the antorbital fenestra. Heavy crests over the orbits. Mandibular fenestra is reduced. Suborder Theropoda. II. Advanced Theropods. A. Infraorder Tetanurae. 4 Groups. Family Megalosauridae. Family Allosauridae. Carcharodontosaurids. Clade Maniraptorifomres.
It always seems impossible until it is done. Nelson Mandela
Idea Transcript
Dinosaurs: History and Evolution
Dinosaurs: History and Evolution
Order Saurischia
Order Saurischia
“Lizard hipped” (primitive type) - Pubis points forward and the ischium back (Same as the Triassic basal archosaurs) Saurischian
Ornithischian
If teeth are reduced…typically lost from back to front. Tend to lack armor. Antorbital fenestra is retained.
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Order Saurischia Suborder Theropoda = “beast foot” Bipedal carnivores (most, but not all) Once divided into 2 main groups “Carnosaurs” = “Flesh lizards” = large “Coelurosaurs” = “Hollow tail lizards” = small
Theropods in General
Carnosaurs vs. Coelurosaurs Do not seem to be biological division, but are instead do to convergence ~ body size, lifestyle, etc. Cryolophosaurus – (6m, Antarctica)
Theropods in General Meat eaters
Meat eaters Runners
Theropods in General
Clawed hands (3 digits) Most have serrated teeth Teeth are compressed Teeth held loosely in jaw Often very large brains Some with large eyes Lightly built skull Held together loosely Mobile neck
Deinocheirus “terrible hand”
Runners 5 sacral vertebrae Large pelvis for muscles S-shaped femur Elongate foot – reduced digits Hollow bones Stiff tail
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Suborder Theropoda I. Basal Theropods A. Herrerasaurids - Late Middle Triassic of South America
Suborder Theropoda I. Basal Theropods B. Infraorder Ceratosauria - Late Triassic - Late Cretaceous (worldwide) - Fusion of the pelvic bones in the adults
B. Infraorder Ceratosauria Coelophysis = “hollow form” - 0.8-3.1 meters long Oldest ceratosaur Late Triassic of North America - New Mexico Well known (100’s of individuals)
Coelophysis
Coelophysis
B. Infraorder Ceratosauria Dilophosaurus = “two crested lizard” 2 crests on the head – Crests common to ceratosaurs Jurassic of North America and China 5-7 meters
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Dilophosaurus
Dilophosaurus
B. Infraorder Ceratosauria Ceratosaurus = “horned lizard” Pair of horns on the nasal bone Jurassic of North America 5-7 meters
B. Infraorder Ceratosauria Carnotaurus = “carnivorous bull” Horns above orbits Cretaceous of Argentina 7.5 meters
Ceratosaurus
Carnotaurus
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Suborder Theropoda II. Advanced Theropods A. Infraorder Tetanurae – “stiff tail” Maxillary fenestra Tooth row does not extend past the antorbital fenestra Skull is short and narrow from side to side
Suborder Theropoda II. Advanced Theropods A. Infraorder Tetanurae Orbit is higher & smaller than the antorbital fenestra Heavy crests over the orbits Mandibular fenestra is reduced
Suborder Theropoda II. Advanced Theropods A. Infraorder Tetanurae 4 Groups Family Megalosauridae Family Allosauridae Carcharodontosaurids Clade Maniraptorifomres
Suborder Theropoda
Megalosaurus
II. Advanced Theropods A. Infraorder Tetanurae 1. Family Megalosauridae Megalosaurus = “big lizard”- mid Jurassic, Europe
9 meters long
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Suborder Theropoda II. Advanced Theropods A. Infraorder Tetanurae 2. Family Allosauridae Allosaurus = “different lizard” - Late Jurassic of North America - 12 meters long
Allosaurus Allosaurus
Allosaurus
“Saurophaganax” = Allosaurus
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“Saurophaganax” = Allosaurus
Suborder Theropoda II. Advanced Theropods A. Infraorder Tetanurae 3. Carcharodontosaurids Radiated worldwide Large carnivores Carcharodontosaurus = “shark-tooth lizard” 1.5m skull!
Carcharodontosaurus
Suborder Theropoda II. Advanced Theropods A. Infraorder Tetanurae 4. Clade Maniraptoriformes = “hand thief shape” Share many derived characters with birds Elongate metacarpal III - reduced metacarpal I Modified caudal vertebrae Downwardly directed pubis Absence of the fourth trochanter on the femur
Suborder Theropoda II. Advanced Theropods A. Infraorder Tetanurae 4. Clade Maniraptoriformes Compsognathus “delicate jaw” 3.5 kg. and 60 cm long
Compsognathus
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Suborder Theropoda
Deinonychus
II. Advanced Theropods A. Infraorder Tetanurae 4. Clade Maniraptoriformes a. Family Dromaeosauridae – have sickle claw Deinonychus – “terrible claw” 3 meters long and about 1 meter high
Protoceratops vs. Velociraptor Protoceratops vs. Velociraptor
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Velociraptor
Velociraptor
Velociraptor
Velociraptor
Utahraptor – “Thief of Utah”
Microraptor 0.5 m – early K of China
5-7 meters long North America
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Microraptor (Dromaeosaur) Glider?
Microraptor
Microraptor
Suborder Theropoda
Oviraptor
II. Advanced Theropods A. Infraorder Tetanurae 4. Clade Maniraptoriformes b. Family Oviraptoridae Oviraptor – “egg raider/thief” ???
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Oviraptor
Oviraptor – “egg raider/thief” ??? Bum rap?
Oviraptor – “egg raider/thief” ??? Bum rap….Yes!
Suborder Theropoda II. Advanced Theropods A. Infraorder Tetanurae 4. Clade Maniraptoriformes
c. Arctometatarsalia – “Narrow column foot” 3 Families – All share: three central metatarsals are triangular in cross section and compressed - metatarsal III often does not articulate with the astragalus
Suborder Theropoda II. Advanced Theropods A. Infraorder Tetanurae 4. Clade Maniraptoriformes
Tyrannosaurus - Up to 14 meters long - Short forelimbs - Extra joint on the mandible = wider gape
c. Arctometatarsalia - 3 Families 1. Family Tyrannosauridae Late Cretaceous of North America & Asia Tyrannosaurus = “tyrant lizard”
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Tyrannosaurus (left) and Dromaeosaur (right)
Tyrannosaurus
Tyrannosaurus
Tyrannosaurus
Sue (Tyrannosaurus rex)
Sue (T. rex)
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Sue (T. rex)
Sue (T. rex)
Sue (T. rex)
Sue (T. rex)
Skull of Sue (Tyrannosaurus rex) - Larson Brothers
Was Sue really female? – problems with negative evidence…
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Tyrannosaurus Hunter or Scavenger?
Tyrannosaurus Hunter or Scavenger? Large olfactory bulbs
Tyrannosaurus Hunter or Scavenger?
Tyrannosaurus Hunter or Scavenger?
Tyrannosaurus rex tooth Note serrations
Suborder Theropoda II. Advanced Theropods A. Infraorder Tetanurae 4. Clade Maniraptoriformes
c. Arctometatarsalia - 3 Families 2. Family Troodontidae Late Cretaceous of North America & Mongolia Saurornithoides = “lizard bird form”
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Saurornithoides *Has been placed within the Dromaeosauridae by some workers
Long slender skull Binocular vision Large brain 3 functional digits only (metatarsal III is the longest)
Suborder Theropoda II. Advanced Theropods A. Infraorder Tetanurae 4. Clade Maniraptoriformes
c. Arctometatarsalia - 3 Families 3. Family Ornithomimidae Late Jurassic though Late Cretaceous Very bird like with long arms and legs Struthiomimus Ornithomimus Gallimimus