View
0
Download
0
Category
Preview:
Citation preview
Evolution of Archosaurs
or “ruling reptiles”
Theropod Dinosaurs
Coelurosaur theropods
Deinonychus
Tyrannosaurus
Carnosaur theropods
Trends in the evolution of birds
• Enlargement of eyes and brain
• Increased metabolic rate
• Loss of teeth
• Lengthened of forelimb as wing
• Keeled breastbone for flight muscles – carinate sternum
• Pennaceous feathers for flight
• Loss of digits, claws, and fusion of bones in wing – carpometacarpus
• Loss of digits and fusion of bones in foot – tarsometatarsus
• Loss and fusion of bones in tail – pygostyle
• Reversal and spreading of pubic bones – large eggs, respiration?
Scipionyx
Preserved viscera
Sinosauropteryx
Cretaceous
Downy feathers
Sinornithosaurus – Cretaceous China
Downy head feathers
wing feathers
Caudipteryx
Cretaceous
China
Caudipteryx reconstruction
Jehelornis
Cretaceous China
Jehelornis
Cretaceous China
tail plume
Protoarchaeopteryx
reconstruction
Rahonavis
Cretaceous
Madagascar
Rahonavis
Cretaceous
Madagascar
Bird or Dromaeosaur?
Deinonychus
Microraptor - four-winged dromaeosaur
Cretaceous
Microraptor - Cretaceous
leg feathers
Archaeopteryx
Jurassic
Archaeopteryx reconstruction
Iberomesornis
Enantiornithes
Early Cretaceous
Spain
tail
Pygostyle - fused caudal vertebrae
Bohaiornis
Enantiornithes
Cretaceous
China
Thin section through bone
resting lines
Confuciusornis
Early Cretaceous
China
toothless beak
fused pygostyle
powered flight
Confuciusornis
Early Cretaceous
China claws on wing
Neornithes - modern birds
Anneavis
Cenozoic Early Eocene fused carpometacarpus
fused tarsometatarsus
fused carpometacarpus
fused tarsometatarsus
fused pygostyle
carinate sternum
Recommended