Pterosaurs D2

 Over that time, the earliest pterosaurs evolved into different species of pterosaurs that varied widely

They did not just jump or glide on the wind. Rather, they flapped their wings to travel by air.

Some pterosaurs had complicated crests on their head.

Pterosaurs were the first animals after insects to fly using their own power.

Their ancestors' heads evolved into wings because their bones grew longer and lighter over time.

Their ancestors' front legs evolved into wings because their bones grew longer and lighter over time.

Their ancestors' wing bones evolved into longer and lighter wing bones over time.

Their ancestors' tails evolved into wings because their bones grew longer and lighter over time.