According to a new study that examined the wing structure of three Archaeopteryx specimens, the animals which have been assigned to the late Jurassic period (150 mil. years old) likely flew short distances through the use of a quick flapping action (very much like modern birds). This is news because, according to extant literature, dinosaurs of this type were incapable of this kind of flight but were rather thought to be gliders.
https://www.nature.com/articles/s41467-018-03296-8
As with so much, what was thought to be set in stone is now up in the air (puns intended).
-B.C.