No. Pterosaurs ('winged reptiles') ruled the skies during the Jurassic and Cretaceous. Although they are not classed as dinosaurs they are very closely related. They first appear in the Late Triassic and became extinct at the K-T boundary.
Like most animals groups the pterosaurs varied greatly. The largest was a Late Cretaceous pterosaur called Quetzalocatlus northropi. The measurement from one wingtip to the other (the wingspan) was 12m. That is the size of some small aircraft! Other pterosaurs were more modest in scale with wing spans of 0.5m up to 2m. This is not suprising if you think about it. A big carnivore needs lots of food, so an ecosystem can only support a few. The same ecosystem can can support far more small to medium sized individuals. Sometimes it pays to be small! The smallest fully grown pterosaurs had wingspans of about 0.25cm, or about as big as a large human hand.
Once it was thought that pterosaurs did not flap their wings but glided. However evidence for active flapping of the wings has come to light since.The evidence from the skeletons of pterosaurs is that the shoulder joint socket is reversed in orientation. Instead of pointing backwards it points forwards. Birds have exactly the same modification to allow them to flap their wings. If pterosaurs did not flap their wings there would be no point in possessing such an adaptation. The bones of pterosaurs are honeycombed, to make them lighter, to aid flight. These delicate bones are the reason why birds and pterosaurs have quite poor fossil records. It is only when they die in a very low-energy environment, such as the Solnhofen limestone of Germany that these bones are well preserved. The image below is of Germandactylus one of the pterosaurs from the Solnhofen. However some of the giant pterosaurs would probably have soared when they could to save energy, just as eagles do today. Do you run everywhere? Probably not. So why should pterosaurs do the aerial equivalent?
This specimen of Germanodactylus is well preserved. Nearly all the delicate bones are present. The 30cm ruler gives you an idea of the size of the pterosaur. Thanks to Dr Dave Unwin for allowing me to photograph this specimen.
The other major discoveries that indicate that pterosaurs flew actively is the finding that pterosaurs had hearts like mammals. Such hearts have four chambers and are designed for an active way of life. Cold blooded animals rely on external heat sources for much of their energy, pterosaurs did not. Pterosaur fossils with fur preserved have been known about for over a century now. Fur is for insulation, to keep body heat in. This is another piece of evidence that indicates that pterosaurs were active and wam-blooded.
To fly actively take a lot of energy. Many food sources were exploited by pterosaurs. During the Jurassic the pterosaurs were significant consumers of fish. It was once thought that they could dive like modern gannets, but further studies have shown that they could not pull their wings in close enough to their bodies to do this.
Investigations of the inside of pterosaur skulls have revealed that the pterosaurs had brains evolved for fine flight control, and the position of their eye sockets indicates that they had binocular vision for judging distances, just like you do.
Such vision and control would have allowed the pterosaurs to skim the surface of the water and grab fish in their beaks. Many species had spearlike teeth which could have been used to harpoon their prey, and long tails to help to maintain control as they fished. Some pterosaurs may have been grabbed by predators in the water as they skimmed the surface. The evidence for this comes from pellets coughed up by some of these predators. The bones of pterosaurs have been found in these pellets, indicating that pterosaur had been on the menu! Other pterosaurs used this fine aerial control to hunt insects on the wing. Many large carnivores scavenge when they can and hunt when they must. It is much easier. Quetzalocatlus northropi may have done this, like a huge vulture. The desert conditions in North America at that time would have been ideal. A pterosaur from rocks in Argentina,Pterodaustro has been found with a bill like that of a flamingo. In the bill were 400-500 slender, bendy teeth that it used to filter the water for tiny plants and animals called plankton.
From this brief survey it can be seen that pterosaurs occupied many of the ecosystem
niches that birds and bats do today, although they were never as