In a time when dinosaurs and birds both co-existed how do they tell the difference between dinosaur feathers and bird feathers? What are the features of feathers between these species that differentiate them?
"We can be sure of the source because the vertebrae are not fused into a rod or pygostyle as in modern birds and their closest relatives," he explained.
"Instead, the tail is long and flexible, with keels of feathers running down each side."
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The feathers lack the well-developed central shaft - a rachis - known from modern birds. Their structure suggests that the two finest tiers of branching in modern feathers, known as barbs and barbules, arose before the rachis formed.
Enantiornithines had the wing joint inverted: https://en.wikipedia.org/wiki/Enantiornithes
"Enantiornitheans are thought to have left no living descendants ... the articulation of the shoulder bones – which has a concave-convex socket joint that is the reverse of that of modern birds"
If anyone can elucidate, please do.
At the bottom of the article is a link to another article on these creatures https://www.bbc.co.uk/news/science-environment-36651471 "Ancient birds' wings preserved in amber"