The Duck That Could Not Float (Paperback) (ISBN-13: 9798897853694)

The inspiration for this story was the discovery of four mudstone toys along a river in southwestern Kentucky, USA. The stone objects were found closely together a few feet in front of a small cave. They were found at a depth slightly deeper than some nearby animal bone fragments that were radiocarbon dated at 3,200 years old. The site was a flint/chert quarry and a tool production site. Authenticated artifacts from the general area date between 1000 and 8,500 years before present.