This is from Benjamin Radford, managing editor of the Skeptical Inquirer science magazine:
…the fatal flaw in the idea that giant dinosaurs still lurk in remote jungles or cold, deep lakes is that all the evidence suggests they died out about 65 million years ago. Many of the lakes said to hide dinosaurs were created only about 10,000 years ago.
If dinosaurs had existed up until much more recently — say, the Nixon administration or even Shakespeare’s time — the likelihood of a few remaining, lonely huge dinosaurs might be plausible. But 65 million years is a long time for giant dinosaurs to live and die without leaving any recent fossils.
Yet scientifically speaking, not all dinosaurs died out. Most of us see dinosaurs every day, and some people even have them in their homes. Birds are the modern version of dinosaurs, though seeing Will Ferrell or Jeff Goldblum running terrified from an approaching pigeon just isn’t very dramatic.
Birds? Benjamin, what about the Coelacanth?
Coelacanth (pronounced /ˈsiːləkænθ/, adaptation of Modern Latin Cœlacanthus: cœl-us + acanth-us from Greek κοῖλ-ος [hollow] + ἄκανθ-α [spine]) is the common name for an order of fish that includes the oldest living lineage of gnathostomata known to date. The coelacanths, which are related to lungfishes and tetrapods, were believed to have been extinct since the end of the Cretaceous period, until the first Latimeria specimen was found off the east coast of South Africa, off the Chalumna River in 1938. They are, therefore, a Lazarus taxon. Since 1938, Latimeria chalumnae have been found in the Comoros, Kenya, Tanzania, Mozambique, Madagascar, and in iSimangaliso Wetland Park, Kwazulu-Natal in South Africa. The second extant species, L. menadoensis, was described from Sulawesi, Indonesia in 1999. The coelacanth has no real commercial value, apart from being coveted by museums and private collectors. As a food fish the coelacanth is almost worthless as its tissues exude oils even when dead, imparting the tough flesh with a foul flavour.