Bats and Ambopteryx
Bats, flying squirrels, and extinct pterosaurs have membranous wings held in place by a special bone called the styliform. That’s convergent evolution in action, but dinosaurs also co-opted this strategy, in which wings are formed from webbing around super-elongated fingers. This revelation was only made in 2019, following the discovery of Ambopteryx longibrachium, a tiny Jurassic dinosaur with membranous wings.
