Cryptoterrestrial UFO hypothesis
From the UAP Encyclopedia, the open encyclopedia of UFO and UAP history · 📖 Term
Contents 7
| Type | Term |
|---|---|
| Also known as | cryptoterrestrial hypothesis, cryptoterrestrials, crypto-terrestrial |
The cryptoterrestrial UFO hypothesis is the idea that UFOs are evidence of a hidden, technologically advanced civilisation native to Earth rather than visitors from space. The term "crypto-terrestrial" was coined in the 2000s by the American writer Mac Tonnies, whose book The Cryptoterrestrials was published after his death, in 2010.[1][2] Scholar Aaron John Gulyas has described the idea as more of a thought experiment meant to raise questions than a firm theory.[1]
Antecedents

Stories of hidden races go back long before the UFO era. Jules Verne's Journey to the Center of the Earth (1864) imagined a world beneath the surface. The anonymous novel The Coming Race (1871) described a subterranean race with mental powers, and H. G. Wells's The Time Machine (1895) featured the underground Morlocks.[1] Theosophist Helena Blavatsky spread tales of hidden masters in Tibet, and occultists placed secret superhuman societies in places such as Shambhala, Atlantis, Lemuria and a hollow Earth.[1]
The Shaver mystery

In the mid-1940s the pulp magazine Amazing Stories, edited by Raymond Palmer, published the claims of Richard Shaver, a Pennsylvania steelworker. Shaver said he was in contact with underground beings who flew disc-shaped craft.[1] In the October 1947 issue, during the first flying disc wave, Palmer argued that the sightings proved Shaver's claims, and Shaver predicted that the truth would never be told to ordinary people.[1] After Shaver's death in 1975, Palmer admitted that Shaver had spent years in a mental institution rather than in underground caverns.[1]
Hidden terrestrials in UFO writing

After Kenneth Arnold's sighting in June 1947, a few writers suggested that the discs were made by beings on Earth rather than from space. Meade Layne proposed that they came from an "etheric plane", and supporters of the hollow Earth idea said they came from a civilisation beneath the surface.[1] Gray Barker's They Knew Too Much About Flying Saucers (1956) suggested an inner-Earth origin, as did Albert K. Bender's Flying Saucers and the Three Men (1962). Raymond Bernard's Flying Saucers from the Earth's Interior (1960) further popularised it.[1] Political scientist Michael Barkun notes that in some conspiracy theories UFOs have underground bases but are still extraterrestrial, while in others they are native to the inner Earth.[1]
Scientific arguments about the shape of alien life have also been cited. Paleontologist George Gaylord Simpson argued in 1964 that intelligent life elsewhere was very unlikely to be humanlike. In 2002 biologist Jack Cohen argued that the "grey" aliens of abduction reports are unlikely to be an extraterrestrial species.[1]
Mac Tonnies

Tonnies (1975–2009) was an American writer on futurism and the paranormal. He contrasted his idea with John Keel's and Jacques Vallée's "ultraterrestrials", which he saw as essentially occult ideas. He asked instead whether the beings of UFO lore might be flesh-and-blood humanoids living hidden on Earth.[1][2] He also compared it with what he called the null hypothesis, that all UFOs are misidentified natural phenomena and conventional aircraft.[1] Tonnies died of a heart arrhythmia in October 2009, aged 34, and The Cryptoterrestrials was published the following year with a foreword by Nick Redfern.[2] The idea has since been discussed by writers including Nick Redfern, Jerome Clark and Harold Puthoff. It is sometimes also called the intraterrestrial or inner-Earth hypothesis.[1]
Recent attention

In the 2025 documentary The Age of Disclosure, Luis Elizondo raised the cryptoterrestrial hypothesis as one possible interpretation of Pentagon UFO reports.[1] Commentators note that even people open to the idea remain skeptical of it.[1]
In fiction
Fiction has used similar ideas, including the 1989 film The Abyss, in which divers meet an advanced civilisation living in Earth's oceans, and a 1996 X-Files episode in which a contactee says his being comes from inside the Earth.[1]
References
- Cryptoterrestrial UFO hypothesis — Wikipedia · en.wikipedia.org · archived copy
- Mac Tonnies — Wikipedia · en.wikipedia.org · archived copy
This page was last edited on 31 October 2026. Articles are written in our own words from the sources listed under References; disputed claims are attributed to the people who made them.
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