Bird to Dinosaur Transition 2 (Dinosaur-Bird Transition (Gradual…
Bird to Dinosaur Transition 2
Dinosaur fossils with feathers = abundant
Atleast 20 species with feathers (1000s skeletons)
Mostly meat-eaters, some plant-eating
Only discovered ~1990s
Chinese 'Feathered Dinosaurs'
Lived around lakes / dense forests near volcano
Ashfall buried dinos suddenly (pyroclastic flow)
Allowed feather preservation
No chance to decay
Protected from predation
Some dinosaurs had feathers
Most convincing evidence birds from dinos ?
Birds only living organisms with feathers
Feathers = complicated structure
Likely only evolved once
Simple filaments / strands
Evolved for simpler use - not wings for flight
insulation & warmth ?
'Furry coated dinos'
First feathers found on Tyrranosaurs
Densely Packed Feathers
Longer & denser packed filaments
Evolved in one lineage of small meat-eating dinos
Lined up on arms & packed closer to body (to begin with)
Branched out, overlapping eachother on arms (later)
Quill Feathers, Zhenyuanlong
Raptor dinosaur with 2 big wings
Could not fly
Muscles not big enough
Arms too short
Feathers on wings & tail (everywhere)
Feathers & Wings Didn't Evolve for Flight
Evolved for Display ?
feathers very colourful & flamboyant
Velociraptor - non-flying dino with feathers
Wings give lift providing:
Body small enough
Wings oriented correctly
Flight developed by accident ?
Smaller body & bigger wings
Dinosaurs developed big feathers on tail, big wings