Exam 1 Flashcards
Kingdom
Animalia
Phylum
Chordata
Class
Aves
Order
-formes
Family
-idae
Archaeopteryx
- MOST IMPORTANT BIRD FOSSIL
- Ancient “bird”
- Transitional form between theropods and birds
- 150 million years ago
Sinosauropteryx
- found in Liaoning China
- dino feathers! flight feathers= exaptation from insulation feathers
- fossilized melanosomes revealed coloration
- discovered in 1996
Yi Qi
- showed gliding flight (like a bat)
- tail used as a rudder (and possibly sexual selection coloration)
- long strong back legs
Exaptation
When a pre-existing structure evolves for e another purpose
Miniaturization
- positive feedback
- new niches (trees)
- escape large predators
Songbirds= Passerines
- order: Passeriformes
- monophyletic group- the same common ancestor
Flight feathers (AKA remiges)
- asymmetrical vane– for lift
- biggest and stiffest
Tail feathers (AKA retrices)
symmetrical vane
Semiplume feathers
- insulation
- intermediates between down and contour feathers
Contour feathers
body feathers, thermoregulation, streamline body during flight, repel H2O
Down feathers
insulation
Filoplume feathers
- hairlike feathers
- rachis, but few to no barbs
- sensory information processing (INCLUDING FLIGHT INFO)
Bristle feathers
- help detect motion of prey
- ex: rictal bristles of Nightjar for channeling food into mouth
Argentavis magnificens
- largest airborne bird
- extinct
- broke the upper limit rule (23 ft wingspan)
- 150lbs
- gliding flight only
How did the force of gravity influence bird evolution
- pneumatic bones
- miniaturization
- no serrated teeth (lighter)
- wing surface area
- no bladder
- increased wing rigidity
Feet function during flight
- takeoff
- landing
Tail function during flight
- stability
- steering
Flight evolved 4 times
- insects 325 mya -wings
- Pterosaur 225 mya (extinct) - extended pinky finger stretched with skin
- birds 150 mya - rigid feather wing
- bats 50 mya - 3 lengthened digits covered in receptors fine-tuned to wind flow
