What could it be?

What kind of creature might Bigfoot be? Perhaps it is an animal thought to be extinct that has really survived.

The coelacanth, for example, is a fish that was thought to be extinct for 60 million years but was found living in South Africa in 1938. Maybe Bigfoot is an ancestor of an early human called a Neanderthal. Or maybe it is a type of giant ape known as Gigantopithecus that scientists believe became extinct 400,000 years ago. Perhaps Bigfoot is an animal that no one has yet been able to prove exists. It is possible. No one knew about the giant panda, for example, until it was first seen in 1937. The Komodo dragon was seen for the first time in 1956.

This is from the "Bigfoot (X Science)" book by Jacqueline Laks Gorman. You can purchase it here.