When pre-industrial peoples across Europe and other parts of the world saw oversized bones eroding out of landforms, they often believed that they could have been the bones of creatures from myths and legends. Elephant skulls seemed as though they could have belonged to cyclops, and a variety of large bones were believed to come from giants or larger-than-life humans.
A researcher at the Museum of Natural History in Berlin has recently published an article about texts dating to the 14th through 19th centuries that talk about discoveries of oversized bones as though they were remnants of animals that existed prior to the Great Flood. Though by the 19th century, most of these claims had been disproven, this researcher was still interested in the body of literature that existed on the topic.
If you have access to an academic library, you may be able to read the full article here. Otherwise, you can read a summary of his findings here, and more about mythical beasts and the reality behind them here.