Trolling through the Internet, one might come across an article. This article could be about "the living dinosaurs of the Congo". Mokele-Mbembe, Kasai Rex (while the two photos are proven to be fakes, people still believe in it), Emela Ntouka, Mbielu-Mbielu-Mbielu, and other stuff I can't even pronounce. Pterosaurs show up too, like the Kongamato from the Congo and the Ropen from New Guinea. Enter proof that all of these could still exist today:
Many of these people are so-called, amateur "cryptozoologists" and they usually say something along the lines of, "The coelacanth was thought to have gone extinct 65 million years ago with the [non-avian] dinosaurs, and yet we found it. Obviously, [non-avian] dinosaurs could still exist today."
I'm going to make the answer clear, short, and simple: No. Just no. A coelacanth is a 5ft long fish that lives 90-700m underwater; its environment has scarcely changed over the years. Meanwhile, the terrestrial world got hotter, tropical forest sprung up over the world, many getting gradually displaced by grasslands, deserts were once swamps, etc. That's a huge environment change. Plus, Mokele-Mbembe is reported to be at least 30ft long. How does a school bus-sized animal (which would eat as much, if not more than an elephant daily) go unnoticed for all these years? Same with the other "living" non-avian dinosaurs. A five foot fish that lives in the abyss is not proof for a school-bus sized, highly specialized creature that eats more than 200lbs of food a day existing! Get over it.