Flightless Birds (4)

In the idea that I am presenting, the basal pterosaurs developed into primitive flying birds (with  feathers and long bony tails) during the Cretaceous. A branch of those flying birds developed into the primitive flightless creatures of the Cretaceous such as the Ornithomimosauria .
For example, Struthiomimus is a genus within the family of Ornithomimosauria.
http://en.wikipedia.org/wiki/Struthiomimus
"Struthiomimus (meaning "ostrich mimic", from the Greek στρουθιον/strouthion meaning "ostrich" and μιμος/mimos meaning "mimic" or "imitator") is a genus of ornithomimid dinosaur from the late Cretaceous of Alberta, Canada. It was a long-legged, ostrich-like dinosaur  [primitive bird]."

In fact, it was not a dinosaur, but was a flightless bird that had developed from the basal pterosaur line. Such a bird is called a "secondarily flightless bird". (It is called "secondarily flightless" because they developed from creatures that were able to fly).
More to come.