Lionking
Having recently visited the Loch Ness Exhibition Centre, it is quite evident how humans can create mythical creatures from logs floating in the water, water waves, catfish, sturgeon, swimming deer... you name it. All Loch Ness monster sightings are explained quite rationally. The same arguments are readily applied to the statues and paintings in your links. Throughout human history, there is a record of our interest with mythical creatures.
Taking on board Jason's post, it is well accepted that humans originate from Africa with evolutionary drivers set in action about 2 million year ago. It is also fairly well accepted that the dinosaur fossil record stopped abruptly around 65 million years ago. Humans and dinosaurs did not coexist, other than in the films with Rachel Welch. According to those films, the cavemen wore watches too.