Cryptozoology (from Greek , kryptos, "hidden" + zoology; literally, "study of hidden animals") is a pseudoscience involving the search for animals whose existence has not been proven due to lack of evidence. The animals cryptozoologists study are often referred to as cryptids, a term coined by John Wall in 1983. This includes living examples of animals that are otherwise considered extinct, such as non-avian dinosaurs; animals whose existence lacks physical evidence but which appear in folklore, such as Bigfoot and Chupacabra; and wild animals dramatically outside their normal geographic ranges, such as phantom cats (also known as Alien Big Cats).