Evolution of Birds

Here is a preliminary flow of the evolution of flying birds:
Pterosaurs ---> Primitive flying birds (eg. Dromaeosauridae, Enantiornithes, Troodontidae etc)
---> Modern flying birds (Neognathae).

Here is a preliminary flow of the evolution of flightless birds:
Pterosaurs ---> Primitive flying birds (eg. Dromaeosauridae, Enantiornithes, Troodontidae etc)
---> Primitive flightless birds (Ornithomimosauria, flightless Dromaeosauridae etc) ----> Modern Ratites (ostrich, emu etc)