Assertion: feather | /r/CapableOf | evolve on dinosaur
Facets:
value: due to their insulation properties
type: CAUSE
value: originally
type: OTHER
Source sentences:
text: One theory suggests that feathers originally evolved on dinosaurs due to their insulation properties; then, small dinosaur species which grew longer feathers may have found them helpful in gliding, leading to the evolution of proto-birds like Archaeopteryx and Microraptor zhaoianus.