if you go to china/japan etc dragons are depicted everywhere
1. Reptiles are universally present on Earth, except at the poles.
2. Reptiles are extremely odd looking to us mammals, being as they are rather far from being related to us. Many of them, especially snakes, are ill tempered and dangerous. Most of them have relatively impressive, sharp choppers. This makes them a rather natural source for monstrous creatures.
3. There is absolutely no evidence of the existence of any creature of 'dragonlike' nature beyond the obvious large reptiles (Gila and monitor lizards) and dinosaurs, which were unquestionably dead long before humans (whose remains may have given the impression of extremely large reptilian monsters).
4. Griffon and Sphinx-like monsters are also a common theme in mythology, nonetheless they are not only false but more or less biologically/evolutionarily impossible.
So, no, by any reasonable criteria of history or biology, dragons did not and do not exist.