Cryptozoology is the study of rumored or mythological animals that are presumed (at least by the researcher) to exist, but for which conclusive proof does not yet exist; or are generally considered extinct, but occasionally reported. Those who study or search for such animals are called cryptozoologists, while the hypothetical creatures involved are referred to by some as "cryptids".
Invention of the term is usually attributed to zoologist Bernard Heuvelmans, who coined the word to mean "the study of hidden animals". Huevelmans' monumental 1955 book, On The Track of Unknown Animals is often seen as the disipline's genesis, but Huevelmans himself traced the scholarly origins of the discipline to Anthonid Cornelis Oudemans and his 1892 study, The Great Sea Serpent.
Huevelmans argued that cryptozoology should be undertaken with scientific rigor, but also with an open-minded , interdisciplinary approach. Furthermore, according to Heuvelmans, special attention should also be given to folklore regarding creatures. While often layered in unlikely, fantasic elements, folktales may contain grains of truth that could help guide those researching reports of unusual animals.
Some cryptozoologists align themselves with a more scientifically rigorous field like zoology, while others tend toward an anthropological slant or even a fortean perspective. The fringes of cryptozoology are often considered pseudoscience by mainstream biologists.
While many cryptozoologists strive for legitimacy and many are respected scientists in other fields, and though discoveries of previously unknown animals are often subject to great attention, cryptozoology per se has never been fully embraced by the scientific community, and one cannot obtain a cryptozoological degree from any college or university.
Recently, however, Henry Gee , editor of the prestigious journal Nature, writes that cryptozoology "can come in from the cold"  due to the unexpected and startling discovery of Homo floresiensis (further details below).
A cryptozoologist may propose that an interest in such a phenomenon does not entail belief, but a detractor will reply that accepting unsubstantiated sightings is itself a belief. Cryptozoologists tend to be responsible for disproving their own objects of study. For example, some cryptozoologists have collected statistical data and studied witness accounts that challenge the validity of many Bigfoot sightings.
Scientists have demonstrated that some creatures of mythology, legend or local folklore were rooted in real animals or phenomena. Thus, cryptozoologists hold that people should be open to the possibility that many more such animals exist.
In the early days of western exploration of the world, many native tales of unknown animals were initially dismissed as mythology or superstition by western scientists, but consequently proven to have a real basis in biological fact. Cryptozoologists often point out that natives often know a great deal more about their immediate environment (and the animals that inhabit it) than western investigators, and therefore suggest that, even today, thus far unproven tales and traditions regarding unknown undescribed animals in native folklore should not be summarily dismissed in the same way.
There are several animals cited as examples for continuing cryptozoological efforts:
- Of an even older lineage than the coelacanth are the Graptolites. Living representatives were first found in 1882, although the group had previously been presumed to have been extinct for 300 million years. Cryptozoologists point these out to demonstrate that there are many unexplored regions of the world left, and that remote exotic locations or specialized ecosystems relatively untouched by man may contain unexpected life.
- Similarly cited is the 1976 discovery of the previously unknown megamouth shark, discovered off Oahu, Hawaii, when it tried to eat a ship's anchor. Some have cautioned against applying the "megamouth analogy" too broadly to hypothetical creatures, noting that while "the megamouth does show that the oceans have a lot of secrets left to reveal ... The megamouth is not a useful analogy to support the existence of marine cryptids" in general. 
- Also cited is the 2003 discovery of the remains of Homo floresiensis, a descendent of Homo erectus which took the anthropological community completely by surprise. The fact that myths of a strikingly similar creature, called Ebu Gogo by the local people, have persisted until as late as the 19th Century has given the field of study new credibility from the rest of the scientific community.
- Cryptozoological supporters have noted that many unfamiliar animals, when first reported, were considered hoaxes, delusions or misidentifications. The platypus, giant squid (and it should be noted that the colossal squid has now been discovered), mountain gorilla, and komodo dragon are a few such creatures. Supporters note that unyielding skepticism may in fact inhibit discovery of unknown animals. Others have suggested a rigid World view disallows many academics from accepting evidence contrary to their preconceptions.
Georges Cuvier's so-called "Rash Dictum " is sometimes cited as a reason that researchers should avoid "rash" conclusions: In 1821, Cuvier remarked that it was unlikely for any large, unknown animal to be discovered, not because they aren't conspicious, but because there aren't that many. Many such discoveries have been made since Cuvier's statement (though less than 50 in number). It's been argued that the chances of uncovering large, previously unknown vertebrates are very slender when compared to uncovering unknown invertebrates. It is the commitment to spectacular animals (mostly vertebrates) that makes cryptozoology's critics suspicious of sensationalism.
Along similar lines, the emblem of the Society for Cryptozoology is the okapi, a forest-dwelling relative of the giraffe that was unknown to Western scientists prior to 1901.
Notable topics of interest in cryptozoology
Primates and man-apes
Sea and lake monsters
General terms for cryptids
There are also some areas of cryptozoology that deal with "mysterious" animals, though in some cases this could also be considered forteana or parapsychology:
Due to some fields of study in cryptozoology, see also pseudoscience and protoscience.
Lakes in which sea monsters are said to live
- Loch Ness (Scotland)
- Loch Morar (Scotland)
- Lough Keane (Ireland)
- Lough Ree (Ireland)
- Lough Muck (Ireland)
- Storsjön (Sweden)
- Lake Okanagan (Canada)
- Lake Champlain (USA/Canada)
- Kleifarvatn (Iceland)
- Menbu-See (China)
- Tian-Chi-See (China)
- Flathead-See (Montana/USA)
- Lake Simloe (Toronto/Canada)
- Manitoba See (Manitoba/Canada)
- Faymouth Ency (Cornwall/England)
- Lake Miosa (Scandinavia)
- Seljordsvatnet (Norway)
- Lake Tahoe (USA)
- Vansee (Turkey)
- Jerome Clark, ‘’Unexplained! 347 Strange Sightings, Incredible Occurrences, and Puzzling Physical Phenomena’’, Visible Ink Press, 1993.
- Bernard Heuvelmans, ‘’On The Track Of Unknown Animals’’, Hill and Wang, 1958