Evolution Dinosaurs Dinosaur Cladogram Originally Deinonychus Clearly a

Deinonychus Clearly a warm-blooded predator Not some oversized, lumbering lizard. Clade Deinonychosauria (Troodontidae &

The Feathered Dinosaurs Originally evolved as insulation Possibly a primitive trait for all dinosaurs!

Feathers (cont. ) Analysis of melanosomes allowed scientists to reconstruct the colour of dinosaur

Gliding Feathers adapted to flying. Development of enlarged second toe - useful for climbing

Sinornothosaurus 122 MYA Like Microraptor, had four wings. Flight feathers. Venomous bite. Orange and

The Claw Small Deinonychosaurids began spending more time on the ground. The enlarged claw

Origins of Flapping The larger dromeosaurids were too heavy to fly, but still had

Flapping (cont. ) As smaller lineages emerged from the larger flapping dinosaurs, they were

Extinction As most dinosaurs were going extinct 65 mya, the smallest dinosaurs, the birds,

Six Dinosaur Clades Stegosaurids Ceratopsians Sauropods Tyrannosaurids Hadrosaurids Therizinosaurids

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Evolution Dinosaurs

Dinosaur Cladogram

Originally. . .

Deinonychus Clearly a warm-blooded predator Not some oversized, lumbering lizard. Clade Deinonychosauria (Troodontidae & Dromeosauridae)

The Feathered Dinosaurs Originally evolved as insulation Possibly a primitive trait for all dinosaurs! Fossils from Liaoning show feather impressions. SINOSAUROPTERYX ROUGHLY 140 MYA

Feathers (cont. ) Analysis of melanosomes allowed scientists to reconstruct the colour of dinosaur feathers!

Gliding Feathers adapted to flying. Development of enlarged second toe - useful for climbing trees. MICRORAPTOR GUI - 120 mya

Sinornothosaurus 122 MYA Like Microraptor, had four wings. Flight feathers. Venomous bite. Orange and black feathers. http: //www. youtube. com/watch? v=w. Iro. Cm. C 5 y. Tg

The Claw Small Deinonychosaurids began spending more time on the ground. The enlarged claw that evolved to climb trees became useful for holding down prey. Claw could be used to climb larger prey, or attack prey’s jugular. VELOCIRAPTOR & PROTOCERATOPS

Origins of Flapping The larger dromeosaurids were too heavy to fly, but still had the flight feathers from their gliding ancestors. Wings could be used for steering. A flapping motion developed while holding down prey. http: //www. youtube. com/watch? v=68 BPPVVp. N 7 s

Flapping (cont. ) As smaller lineages emerged from the larger flapping dinosaurs, they were able to use that flapping motion for propelled flight. RAHONAVIS

Extinction As most dinosaurs were going extinct 65 mya, the smallest dinosaurs, the birds, were able to survive. Modern birds are classified as theropod dinosaurs. Paedomorphy is the act of resembling an infant form. Near the end of the cretaceous period, selection favoured those raptors which resembled babies, and were light enough to fly. Birds are paedomorphic dinosaurs.

Then. . .

Now

Six Dinosaur Clades Stegosaurids Ceratopsians Sauropods Tyrannosaurids Hadrosaurids Therizinosaurids

Stegosaurids

Ceratopsians

Sauropods

Tyrannosaurids

Hadrosaurids

Therizinosaurids