What Kind of Creatures are Included in Cryptozoology?
According to Dr. Bernard Heuvelmans, there are 5 specifics that make creatures count as cryptids. From his paper “Annotated Checklist of Apparently Unknown Animals with which Cryptozoology is Concerned” published in 1986, a cryptid can be any of the following things:
“1) A species or subspecies apparently unknown to science, including alleged prehistoric survivors (e.g. mokele-mbembe).
“2) A species or subspecies presently unknown to science in the living state, but which is known to have existed in historical times and allegedly still persists today (e.g. thylacine).
“3) A species or subspecies known to science but allegedly existing as a natural occurrence in a location outside its scientifically-recognised current geographical distribution (e.g. pumas in eastern USA).
“4) A species or subspecies known to science but allegedly existing as an artificial occurrence (i.e. due to human intervention) in a location outside its scientifically-recognised current geographical distribution (e.g. alien big cats in Britian).
“5) An unrecognized non-taxonomic variant of a known species or subspecies (e.g. Fujian blue tiger; prior to its scientific recognition, the journal [of Cryptozoology]’s logo creature, the king cheetah, was another example from this category).”
In addition to these 5 criteria, there was a note in one paper that states that “mythological beasts will be considered […] if their subjects have direct relevance to cryptids (e.g. the similarity between a given lake monster from folklore and cryptids reported in the same lake in modern times).”