Beaks

Let's get down to a basic characteristic that pterosaurs and basal paraves share:

http://en.wikipedia.org/wiki/Pterosaur

Most pterosaur skulls had elongated jaws with a full complement of needle-like teeth.[26] In some cases, fossilized keratinous beak tissue has been preserved, though in toothed forms, the beak is small and restricted to the jaw tips and does not involve the teeth.[27] Some advanced beaked forms were toothless, such as the pteranodonts and azhdarchids, and had larger, more extensive, and more bird-like beaks.[26]

http://theropods.wikia.com/wiki/Scansoriopterygidae

Scansoriopterygidae dinosaurs were very small, bipedal dinosaurs, the size of sparrows and pigeons. They had also a few quite amazing features, such as a unusually long third finger on the hand, beaks, and very short tails with very long feathers at the end of it.