While used by most cryptozoologists, the term "cryptid" is not used by academic zoologists. In a textbook aimed at undergraduates, academics Caleb W. Lack and Jacques Rousseau note that the subculture's focus on what it deems to be "cryptids" is a pseudoscientic extension of older belief in monsters and other similar entities from the folklore record, yet with a "new, more scientific-sounding name: cryptids". While biologists regularly identify new species, cryptozoologists often focus on creatures from the folklore record. Most famously, these include the Loch Ness Monster, Bigfoot, the chupacabra, as well as other "imposing beasts that could be labeled as monsters". In their search for these entities, cryptozoologists may employ devices such as motion-sensitive cameras, night-vision equipment, and audio-recording equipment. While there have been attempts to codify cryptozoological approaches, unlike biologists, zoologists, botanists, and other academic disciplines, however, "there are no accepted, uniform, or successful methods for pursuing cryptids". Some scholars have identified precursors to modern cryptozoology in certain medieval approaches to the folklore record, and the psychology behind the cryptozoology approach has been the subject of academic study. Few cryptozoologists have a formal science education, and fewer still have a science background directly relevant to cryptozoology. Adherents often misrepresent the academic backgrounds of cryptozoologists. According to writer Daniel Loxton and paleontologist Donald Prothero, "Cryptozoologists have often promoted 'Professor Roy Mackal, PhD.' as one of their leading figures and one of the few with a legitimate doctorate in biology. What is rarely mentioned, however, is that he had no training that would qualify him to undertake competent research on exotic animals. This raises the specter of 'credential mongering', by which an individual or organization feints a person's graduate degree as proof of expertise, even though his or her training is not specifically relevant to the field under consideration." Besides Heuvalmans, Sanderson, and Mackal, other notable cryptozoologists with academic backgrounds include Grover Krantz, Karl Shuker, and Richard Greenwell. Historically, notable cryptozoologists have often identified instances featuring "irrefutable evidence" (such as Sanderson and Krantz), only for the evidence to be revealed as the product of a hoax. This may occur during a closer examination by experts or upon confession of the hoaxer.