“Cryptid” has become a term describing pretty much any unidentified animal, much as such mysteries were known as “the what-is-it” in earlier times. Particular “species” of mystery animal, for example the Sasquatch or Loch Ness Monster, are known by the name of cryptid; likewise the term is more loosely applied to more paranormal things; sightings of out-of-place animals and animals thought extinct; and even singular sightings different from any other cryptid or known species is not infrequently called by the name cryptid.
Cryptid Species
The base definition of the term “cryptid” applies to mystery animals (supposedly including animals out of place or time; the author disagrees with this, as will be discussed below) for which there is a body of evidence, including sightings, and perhaps photographs and physical evidence such as tracks. In the mind of this author, this should be the only use for this term: that is to say, species that appear to be undescribed by science. Why? Because this is what Cryptozoology is primarily concerned with. Even mystery animals with paranormal associations and attributes should be issued this name only with great caution, perhaps in the light of information that seems to indicate that they are normal animal species.
In the Wrong Part of the World
If one sees a kangaroo in North America, or a puma in Great Britain, it is more than likely to be labeled a cryptid (in fact, exactly that has happened). But regardless of where they came from, and regardless of whether they have established a population, they are not new species. Such so-called “out-of-place” animals, while certainly of interest, do not exactly fall within the core of Cryptozoology. More to the point, with the existence of terms like “out-of-place” and “feral population”, there is little reason to cloud the definition of the term “cryptid” with animals which, even if living in a region they are not documented to live in, do not constitute new species.
Survivors of Extinction
Here there is a gray area in the definition of a cryptid. Let us define two types of living animals thought extinct: first there are the animals extinct in recent times (that is to say, the Holocene period), sightings of which persist into the present day (for instance the Thylacine [Thylacinus cyncocephalus] or the Ivory-billed Woodpecker [Campephilus principalis]). Secondly there are the so-called “prehistoric survivors” or “living fossils”, extant animals belonging to ancient groups yet relatively unchanged from the ancient forms (coelacanths [Latimeria chalumnae], tuataras [Sphenodon sp.], and cockroaches [order Blattodea] are known as living fossils; supposed living dinosaurs or ancient mammals are called prehistoric survivors). It is somewhat borderline as to whether to call an example of the former a cryptid, for while they are not new species, they are species or subspecies which are not thought to exist in the present day. For this reason they can reasonably be called cryptids.
A Singular Occurrence
Finally we come to the matter of sightings that bear little resemblance to known animals or cryptids. These will be sightings by a person who cannot identify what they have seen. They could be any number of things, but most of the time they will not be very detailed, the person not having had much of a chance for observation. In cases like these, people, especially those who saw the mystery animal in question themselves, will be quick to jump to the term “cryptid”. However, singular occurrences could, in most cases, be just about anything. Without being able to observe details, potentially important details, there is little telling what the said mystery animal might be. Logic then dictates that it was probably a known species.