Professor Challenger, who with the two local Indians was in the van of the party, stopped suddenly and pointed excitedly to the right. As he did so we saw, at the distance of a mile or so, something which appeared to be a huge gray bird flap slowly up from the ground and skim smoothly off, flying very low and straight, until it was lost among the tree-ferns.
“Did you see it?” cried Challenger, in exultation. “Summerlee, did you see it?”
His colleague was staring at the spot where the creature had disappeared. “What do you claim that it was?” he asked.
“To the best of my belief, a pterodactyl.”
(--Sir Arthur Conan Doyle, The Lost World, Chapter 8; 1912)1
(0. Pterosaur from movie…1,000,000 Years BC)
It’s hard to imagine a scene of dinosaurs without great Pterosaurs soaring overhead. It used to be thought that they were mere gliders, incapable of flapping their vast wings for sustained flight. They were envisioned hanging upside-down from cliff faces, like bats, and dropping into a gliding swoop. But it is now the consensus that the smaller ones flew as well as birds, and the truly huge ones, such as Pteranodon (with a 27-ft wingspan) and Quetzalcoatlus (with a wingspan of forty feet!) could take off as easily as a kite into a light breeze, and soar aloft for days, scarcely moving their mighty wings, much like albatrosses. Evidence has emerged that some of them migrated across entire oceans to reach their nesting grounds.
The first vertebrates to evolve true flight, Pterosaurs (“winged lizards”) were flying reptiles with their front limbs modified into wings of webbed skin like the wings of bats. Since the wing is supported by an enormously elongated little finger, they are also called Pterodactyls (“wing-finger”). They were furry, evidently warm-blooded, with large and sophisticated brains. They ruled the Mesozoic skies from 228-65 million years ago. In the terminology of Medieval Dragonlore, they would be called Wyverns.
Fig. 1. Pteranodon.
The Wyvern (or Wivern) is a kind of flying serpentine Dragon with bat-like wings, two avian hind legs with eagle talons, and a long barbed tail. Basically, it is a Pterosaur, like ramphorhynchus. Variants include the Sea-Wyvern, which has a fish-like tail. Wyverns have been described as the largest form of Dragon, able to prey on such huge creatures as elephants and rhinos. In Heraldry, the Wyvern symbolizes war, pestilence, envy and viciousness. The default coloration of a Heraldic Wyvern is green with a red chest, belly and under-wings.
Fig. 2. Heraldic Wyvern.
Pterosaurs still alive?
Although they are supposed to have been extinct for 65 million years, sightings of apparent living Pterosaurs are still reported from time to time.
Snallygaster (or Snollygoster) was a Pterosaur-like beast said to inhabit the
Blue Ridge Mountains
near . The first German
settlers in the 1730s were terrorized by a monster they called Schnellgeiste (“quick spirit”). It was
described as half-reptile, half-bird, with a metallic beak and razor-sharp
teeth. It swooped silently from the sky to carry off its victims and suck their
blood. Seven-pointed stars to keep the Snallygaster at bay can still be seen
painted on local barns. Braddock Heights, Maryland,
Fig. 3. Snallygaster
In The Illustrated London News (Feb. 9, 1856, page 166) it was reported that workmen cutting a tunnel for a railway line, between Saint-Dizier and
in France, were
blasting through Jurassic limestone when a bizarre winged creature tumbled out
of a cavity. It fluttered its wings, made a hoarse croaking noise, and dropped
dead. According to the workers, the creature had oily black leathery skin, a
3.22-meter wingspan (10-ft 7-in), four long legs with “crooked talons,” joined
by a membrane. The size of “a large goose,” it had a long neck, and a mouth
full of sharp teeth. The body was brought to Gray, where, a paleontology
student identified the animal as a Pterodactyl
anas [“wing-fingered duck”—a non-existent species]2
This incredible story is simply a hoax. At the time, many exquisite fossils were being extracted from
Solnhofen Limestone (which would later yield the famed Archaeopteryx).
Each of these discoveries was triumphantly announced by German paleontologists.
The tunnel in question was through limestone of similar age to the Solnhofen
beds, so some French wags decided to do the Germans one better.3
Fig. 4. Pterodactylus on ground
In Feb.-Mar. 1909, residents of
haunt of the legendary Snallygaster) reported sightings of a creature with
“enormous wings, a long pointed bill, claws like steel hooks, and an eye in the
center of its forehead.” It screeched “like a locomotive whistle.” The
Smithsonian Institute offered a reward for the hide, and President Theodore
Roosevelt considered postponing an African safari to personally hunt for the
beast. But after the initial flurry, nothing more was heard of it. Braddock
From late 1975 through early 1976, people along the lower
Rio Grande valley
between Texas and Mexico
reported a wave of “big bird” sightings. The avian anomalies were described as
impossibly huge, with membranous wings like bats, and often cat-like faces.
In January 1976, two sisters, Libby and Deanie Ford, saw a large strange “bird” standing by a pond outside of
. They said it was as tall as a
person, all black, with a face like a cat. Later, they identified it from a
book as being a pteranodon. Given
their description, this seems like a very odd identification indeed; a
pteranodon’s head looks like a pickax, not a cat! Here is an example from a
1965 sighting by Patty Carson at Brownsville,
Texas : Guantanomo Bay,
Fig. 5. Gitmo Pteranodon.
Pterosaurs in the Old West
One of Ray Harryhausen’s best stop-motion animation movies was Valley of the Gwangi (1969), featuring a lost valley in
where prehistoric animals still thrive. Some of the most dramatic scenes
feature a Pteranodon which attacks mounted cowboys, who then capture it. This
may have been inspired by a remarkable petroglyph (rock painting) of an
apparent pterosaur, painted high on a cliff face, directly under a cave, near
Fig. 6. Pterosaur petroglyph near
. Thompson, Utah
In April of 1890, two cowboys in
allegedly killed an enormous bird-like creature with smooth skin and
featherless leathery wings like a bat. Its head resembled that of an alligator.
They said they had come upon it in the desert, and it was apparently sick or
wounded. The animal managed to take off and fly about half a mile before
sinking to the ground again, where the cowboys finished it off with rifles.
Harry McClure was a young man living in
in 1910 when the two cowboys came to town,
telling of their encounter 20 years earlier. 60 years later, in a letter to the
Summer 1970 issue of Old West Magazine, McClure
recalled their description of the creature: “Its eyes were like saucers; its two legs
and feet up at the front part of its body were the size of those of a horse;
its hide was leathery, instead of feathery. It lit on the ground once at a safe
distance from the two cowboys, but it took to the air again soon afterwards
only to come down again a second time...”4 Lordsburg, New
Fig. 7. Cowboy wrestling Pteranodon, from Valley of the Gwangi.
According to the account published in the April 26, 1890 edition of Arizona’s Tombstone Epitaph, the cowboys paced off the dimensions of their monster as an astonishing 92-ft long, with a wingspan of 160-ft! The cowboys cut off a wingtip and took it into the town of
Plans were made to skin the creature for a museum, but nothing further was ever
But another version of the story is that they dragged the entire carcass back to town, where it was pinned, wings outstretched, across the entire side of a barn. This time, its wingspan was said to be “only” 20-30 ft. This account—supposedly with a photo—was reprinted in 1969, but no one now seems to be able to track down a copy, and the hunt for the elusive photo has itself become a cryptozoological quest. Here is a photo I came across which may or may not be the one:
Fig. 8. Pterosaur supposedly shot in the late 1800s.
A more recent sighting in the American West occurred southwest of
in January 1976. Three schoolteachers were driving to work when a large flying
creature swooped low over the highway at about the height of the phone poles.
It cast a shadow across the width of the road, and by that the women estimated
its wingspan as 15-20 ft. They said they could see the bones of the bat-like
wings through the grey membrane that covered them. Later, at school, they pored
through encyclopedias and found a picture of what they had seen. It was a pteranodon. This story was reported in
the San Antonio Light, Feb. 26, 1976.6 San Antonio, Texas
Another intriguing photo purports to show a dead Pterosaur surrounded by Civil War soldiers, but no further information on it seems to be available:
Fig. 9. Photo of trophy pterosaur during Civil War.
South American Pterosaurs
Legends of giant flying creatures in
predate the arrival of the Conquistadores, and continue into modern times.
Indeed, some of these were surely an inspiration to Arthur Conan Doyle for
setting the locale of his “Lost World” in Venezuela. In April of 1868,
mine workers in , were preparing for supper when they sighted “a gigantic bird, which at first we took for
one of the clouds then partially darkening the atmosphere, supposing it to have
been separated from the rest by the wind.” As it flew over their heads,
they could see that its immense wings were not feathered, but webbed in skin
like those of a bat. This story was reported in the July, 1968 issue of The Zoologist.7 Copiapo, Chile
In February of 1947, Mr. J. Harrison of
, was navigating an estuary of the Amazon when he and
others observed a flight of five huge “birds” flying down the river in a V
formation. In an unpublished letter to the Fortean
Times, Liverpool, England Harrison said: “The wingspan
must have been at least twelve feet from tip to tip. They were brown in colour
like brown leather, with no visible signs of feathers. The head was flat on
top, with a long beak and a long neck. The wings were ribbed…just like those
large prehistoric birds.”8 Here is the drawing he enclosed with his letter:
Fig. 10. J.
Harrison’s drawing of a
“prehistoric bird” he saw over the Amazon in 1947
And in 1992, the Australian weekly magazine People reported a close encounter between a small commuter airplane and a huge flying reptile over the mountains of
The creature appeared alongside as the plane was preparing to land, and the
pilot had to veer away to avoid a collision. Stewardess Maya Cabon said: “Here was this giant monster flying right
next to the plane. He was only a few feet from the window—and he looked right
at me. I thought we were all going to die.” U.S.
anthropologist Dr. George Biles, one of the 24 passengers aboard, elaborated: “This was a classic case of a white
pterodactyl with a giant wingspan. Of course, I’ve heard the rumors for many
years that these prehistoric creatures still roamed the Amazon. But I was
skeptical like everybody else. But that wasn’t an airplane or a UFO flying
beside us. It was a pterodactyl.”9
From swampy regions of
and Kenya come
reports of Kongamato (“Overwhelmer
of Boats”). Numerous reported sightings of these large, leathery-winged flying
creatures have led cryptozoologists to speculate that there may be a relic
population of Pterodactyls still living in Africa.
They are colored black or red, and are named for their proclivity of capsizing
canoes. Frank H. Mellon, in his In
Witchbound Africa (1923),10
described them as smooth-skinned, with toothy beaks and wingspans of 4-7 ft.
Another witness said the wings made a loud thunderous noise when flapped. When
they are shown pictures of pterosaurs, all witnesses immediately identify them
as Kongamoto. It is far more likely, however, that these creatures are actually
Hammerhead Bats (Hypsignathus monstrosus), Africa’s
largest bat species. They are dark gray with black wings spanning three feet,
and have elongated, dog-like snouts.
In 1925, southern Rhodesia produced reports of a Kongamato attack on a man in a swamp, and reports issued from Africa in 1928, 1942, the 1950s, up through modern times, including a colleague of cryptozoologist Roy Mackal’s who saw one in 1988.11
Fig. 11. Kongamato attack, by William M. Rebsamen
Either the same or another gigantic black pterodactyl-like creature was encountered in 1932 in the
of the African Cameroons by zoologist Ivan T. Sanderson and naturalist Gerald
Russell in 1932. As they were crossing a river, it dived at them, then flew
away. Apparently the size of an eagle, it had “pointed white teeth set about
their own width apart from each other” and “Dracula-like wings.” They saw it
again that evening. Locals called the creature Olitiau. Sanderson later
speculated that the beast was probably an exceptionally large specimen of the Hammerhead
Bat. But there’s a huge gap between the 3-ft wingspan of the Hammerhead, and
the 12-ft span Sanderson estimated for the Olitiau! Assumbo Mountains
Fig. 12. Olitiau.
Guiafairo is a great grey flying creature reported from
West Africa, where it hides in caves and hollow
trees during the day, emerging only at night. It has clawed feet and a
human-like head. Cryptozoologists speculate that it may be an unknown species
of giant bat, or another example of the Hammerhead Bat.
Fig. 13. Guiafairo by Ian Daniels
Gigantic flying predators have also been reported in
New Guinea. Called Duah, they have a 24-foot
leathery wingspan, a long, toothless beak and a large head crest, precisely
matching the image of a Pteranodon.
Likewise, they are oceanic fish-eaters, though there are reports of vicious and
fatal attacks on humans.
Fig. 14. Duah by William Rebsamen.
Another Pterodactyl-like creature has been reported from the jungles of
Guinea since the 1950s. The Ropen
(“Demon Flyer”) lives in caves along the islands of New
Britain and Umboi, and flies only at night. It has
leathery wings spanning 3-4 ft, a narrow, tooth-filled beak, a head crest,
webbed feet, and a long tail culminating in a diamond-shaped flange. It is said
to feast on decaying flesh, harassing funerals to attack the corpse. The
description of the tail sounds uncannily like a Rhamphorynchus, believed to have been extinct for 65 million years,
but they didn’t have head crests. I have personally visited several of those
islands, climbed their cliffs, and explored their caves. Alas, I found no
pterodactyls, only fruit bats.
Fig. 15. Rhamphorynchus
It is virtually certain that these New Guinea sightings are all of large fruit bats, most likely the Bismark Flying Fox (Pteropus neohibernicus), with a wingspan of 5.5-6 ft. Recognized by science as the world’s largest living species of bat, it is native to New Guinea and the Bismark Archipelago.
Fig. 16. Bismark Flying Fox (photo by Michael Pitts)
is a fascinating eyewitness account of a sighting of living Pterosaurs in
of 1971. The witness was a Marine named Eskin Kuhn, who reports: Cuba
It was a beautiful, clear Summer day. I was looking in the direction of the ocean when I saw an incredible sight. It mesmerized me!
I saw 2 Pterosaurs flying together at low altitude, perhaps 100 feet, very close in range from where I was standing, so that I had a perfectly clear view of them.
The rhythm of their large wings was very graceful, slow; and yet they were flying and not merely gliding, like turkey vultures do here in
The rate of their wings was more like that of crows, perhaps a little slower; but very graceful. The structure and the texture of the wings appeared to be very similar to that of bats: particularly in that the struts of the wings emanated from a "hand" as fingers would; except that a couple of the fingers were short (as for grasping) and the other ran out to the tip of the wing, others back to the trailing edge of the wing to stretch the wing membrane as a kite would.
Fig. 17. Eskin Kuhn's Pterosaur drawing from life.
The Pterosaurs I saw had the short hind legs attached to the rearwardmost part of the wing, and they had a long tail trailing behind with a tuft of hair at the end.
The head was disproportionately large, with a long crest at the back, long bill, long neck with a crook in it. The chest of the creatures was similarly prominent, protruding forward like the prow of an old ship.
The vertebrae of their backs was noticeable, mostly between the shoulders. I would estimate their wingspan to be roughly 10 feet.12
The excellent drawing Eskin Kuhn made of the creatures he saw strongly matches images of a great blue heron in flight, with its neck crooked and its long legs trailing straight out and together. The “tuft”-tipped tail of Kuhn’s drawing accords with the webbed feet of the heron. And the heron even has a backward-sweeping crest of feathers on its head which resembles the crest of a Pteranodon as Kuhn drew it.
Fig. 18. Great Blue Heron in flight
Hsigo— (or Hsiao) These Chinese creatures are exactly like the flying monkeys from The Wizard of Oz. They have apelike bodies with a dog’s tail, a birdlike head, a human face, and wings—though they are not described as wearing bellhop uniforms! They are probably based on fruit bats, or “flying foxes,” of
These monkey-size bats are not related to the other insectivorous bats, but are
genetically closer to primates, and thus really are a kind of “Flying Monkey.”
Fig. 19. Hsigo
Ahool— Reported from Java and
these are giant bats of an unidentified species. Named for their cry, they are
said to be the size of a year-old child, dark grey, with a head like a monkey.
These would certainly seem to be large fruit bats. The Ahool, however, is said
to be a fish-eater which, if true, would mean it has to be something else.
Fig. 20. Mauritian flying fox in flight (photo by Gregory Guida)
Alan— Mischievous half-human, half-bird creatures from the forests of the
With extended fingers on their backwards-facing feet and stubby toes on their
hands, they spend much of their time hanging upside down from trees. They are
often very helpful toward humans and have served as foster parents to several
legendary heroes whom they found lost in the forest as babies. This
description, and the locale, strongly suggest a large fruit bat, such as the
Malayan Flying Fox.
Fig. 21. Flying fox hanging upside down
Orang-Bati— (“Men with wings”) Predatory nocturnal flying primates from the obscure Indonesian
second largest island in the island of Ceram Moluccas group. The natives
of Ceram describe these soaring simians as approximately
five feet tall, with black leathery wings, blood-red skin, and a long thin
tail. Emitting a “mournful wail,” they are said to abduct infants and small
children. During the day they retreat into a network of caves in an extinct
This description, and the locale, strongly suggests a giant fruit bat—probably,
again, the Malayan Flying Fox. Mount Kairatu
Fig. 22. Malayan Flying Fox
Vietnamese Night-Flyers— Flying humanoids with bat-like wings, sighted by three U.S. Marines in 1969, near
. According to the soldiers’ report,
three naked, hair-covered, feminine figures, all approximately five feet in
height, flew over their post in the dead of night. The Marines claimed they
could hear the flapping of their leathery black wings. These were certainly
Malayan Flying Foxes, of which the females (which have two thoracic breasts
like humans) can have wingspans of six feet, although they weigh only up to
3.3-lbs. Da Nang, South
Fig. 23. Vietnamese Night-Flyer by Tam Songdog
Sassabonsum is a huge evil fruit bat in the folklore of
West Africa. With red hair, hooked wings, and
backwards-pointing feet, it swoops upon people and carries them off at the
bidding of the Mmoatia, or pygmy sorcerers. As with the Kongamoto, Olititau and
Guiafairo, this is probably the Hammerhead Bat.
Fig. 24. Hammerhead bat
In his 1972 book, Investigating the Unexplained, Ivan Sanderson suggested another possible identification for these oversized bat-like creatures; that they may represent a hitherto-unknown enormous species of microbat (Microchiroptera), commonly referred to as “insectivorous bats,” “echolocating bats,” “small bats,” or “true bats.”13
In contrast to the doglike snouts of fruit bats, or megabats (Megachiroptera), microbats have the flattened monkey-like faces described as characteristic of all the above “flying monkeys.” While most of them are insectivorous, some of the larger species hunt birds, lizards, frogs, or even fish—behavior that is often mentioned in regard to these cryptic creatures, and does not occur among any of the megabats. Even vampire microbats exist, though only, as far as is known, in
Fig. 25. Microbat
According to native witnesses, when Ahools are seen on the ground, or perched like a bird on a tree branch, they fold their wings at their sides like a bird, as do all microbats. Megabats, on the other hand, wrap their wings around their bodies like a cloak. Ahools are also said to be able to stand upright on two legs, and in doing so their feet point backwards. Again, only microbats can stand erect (though they seldom do so); megabats can stand only on all fours, or hang upside down from tree branches. But it is true that the hind feet of all bats point backwards.14
The difficulty with this hypothesis is that microbats are well-named. They are all quite tiny, with the largest, the Big Brown Bat (Eptesicus fuscus), attaining a wingspan of only 13 inches. A microbat with a 6-12 foot wingspan seems like an incredible stretch, with nothing in between. However, I have had personal experience which may help put this matter into perspective, so to speak.
One night when we were lying outside watching a meteor shower, a pale ghostly shape swooped down out of the sky, circled our blanket, and then soared off. In the light of our candle, it seemed huge—at least a three-foot wingspan! Even though we knew it had to be a bat, we all agreed that our first impression was of a pterodactyl! So I immediately went to my library and looked up local bats, and lo and behold, there it was: a Pallid Bat (Antrozous pallidus). They eat ground-dwelling crickets and scorpions, so they swoop rather than flitter.
Fig. 26. Pallid Bat
But the thing is—they have a wingspan of no more than 12 inches. So how come it appeared so immensely large to us? Well, as I explained in my article on Sea Serpents, in the sky, as in the open ocean, there is no objective basis of comparison against which to measure an object. A creature flying overhead could, for all you know, be three feet above, and have a 3-foot wingspan. Or it could be ten feet above and have a 10-foot wingspan. Especially at night, there is no way to know. So, like the fisherman whose catch got away, we declare for the largest size. The pallid bat is nearly white on the underside, and it reflected so much illumination from the candle that it appeared to be much larger than it really was.
Fig. 27. Distance perspective diagram by OZ
In addition, as I also mentioned in the Sea Serpent chapter, there is the factor of the automatic “zoom lens” mode that our brain goes into when we see something highly alarming. This evolutionarily adaptive mechanism creates an exaggeration of size in our mind’s eye, just as it does in a camera when we use the zoom lens. And thus are creatures of ordinary size transformed into giants.
As much as I would love to know that somewhere on Earth, pterodactyls still ride the skies, I’m afraid I will just have to settle for extra-large bats.
Pterosaurs in the movies
Pterosaurs and Wyverns have been featured in many movies, in both prehistoric settings of the “Lost World” genre, and as flying Dragons. Pterosaurs are routinely included among dinosaurs, although there have been a few films where they appear in modern times—often hatching in the heart of a volcano from long-dormant eggs. As pterosaurs really were ancient “flying dragons,” it is perfectly reasonable that the appearance of some film dragons should be based on their anatomy, rather than on the less-justifiable model in which two bat-like wings are affixed to the body of a quadrupedal reptile. Excellent examples of such “Wyvern” dragons appear in Dragonslayer (1981) and Dragon Storm (2004).
Rodan (Radon in
is a well-known fictional Pterosaur, introduced in Rodan, a 1956 movie
from Toho Studios, which created the Godzilla series. Like Godzilla, Rodan was
also modeled after a real prehistoric reptile. The Japanese name Radon is a contraction of “pteranodon”
and also suggests radiation. Radon is referred to as Rodan in the U.S.,
possibly to avoid confusion with the atomic element Radon. He was initially
portrayed as an enemy of Godzilla, but they later became allies against more
Fig. 28. Rodan
Here are a number of films featuring living Pterosaurs, Wyverns, and Bat-monsters—omitting those which take place during the Mesozoic Age, or on other planets. The commentary is by Seth Tyrssen:
The Lost World (silent -1925) This is the original version of the famous story, and it still holds its own today. The then-new art of stop-motion animation brought a variety of prehistoric beasties to life, including some very life-like “flying lizards.” King Kong (1933) saw the art of stop-motion animation carried to new heights, and one of its best scenes shows the great ape battling a pteranodon at his mountain retreat, as the hapless heroine Fay Wray looks on…screaming, of course. Rodan (1956) was one of Eijii Tsubaraya’s early works. Japanese animation, as seen in this and a whole slew of Godzilla movies, will never win any awards for realism, but Rodan (like all the others) is amusing because it’s so bad, it’s good. Rodan appears to be a basic pteranodon, more or less. The Land Unknown (1957) and The Lost World (1960) join the ranks of several other bad remakes.
One Million Years BC (1966) is actually a remake of the earlier 1,000,000 BC but featured Raquel Welch in her first major role. The pterosaurs and other monsters are credibly done. The
(1969) featured the work of
Ray Harryhausen, and in spite of a silly premise, is actually quite good. Harryhausen’s
realistic Allosaurus shares space with some well-done pterosaurs, and even an
Eohippus, the first tiny horse. The Land
That Time Forgot (1974) is more notable for lovely Caroline Munroe than for
its creatures, clearly not up to the standards set by Harryhausen, but that was
probably due to the obviously low budget. Dragonslayer
(1981) gave us the first really impressive dragon since Disney’s animated
“Sleeping Beauty,” complete with an engrossing plot. Valley of Gwangi
One Million Years BC (1966) is actually a remake of the earlier 1,000,000 BC but featured Raquel Welch in her first major role. The pterosaurs and other monsters are credibly done. The
Fig. 29. Vermithrax Perjorative, from movie Dragonslayer (1981)
In The Lost World (1992), John Rhys-Davies and David Warner are wonderful, as the philosophically sparring Professors Challenger and Summerlee, respectively. Though the story was seriously altered for “political correctness,” it’s a tolerable version, with tolerable–though not great–critter-animation. Jurassic Park II: the Lost World (1997) Like its predecessor, this one had pterosaurs that looked incredibly real. The special effects folks really did their homework on these films. Jurassic Park III (2001) continues the excellent standards set by the first two films, with a whole host of realistic creatures. The Lost World (BBC-TV, 2001) At last, a worthy remake! Bob Hoskins (of “Roger Rabbit” fame) is teamed with James Fox, and a wide variety of well-done dinos. In this one, his pterosaur escapes into
Lord of the Rings: The
Fig. 30. Pteranodon attack, from Pterodactyl (2005).
1. Doyle, Sir Arthur Conan, The Lost World, Hodder & Stoughton, 1912.
2. Keel, John. A, The Complete Guide to Mysterious Beings, Doubleday, 1970; 1994.
3. Sanderson, Ivan, Investigating the Unexplained: A Compendium of Disquieting Mysteries of the Natural World, Prentiss-Hall, 1972.
4. Hall, Mark A., “The Mystery Of The Thunderbird,” Fortean Times,
6. Michel, Johnl & Rickard, Robert J.M., Living Wonders: Mysteries & Curiosities of the Animal World,
Thames & Hudson,
7. Corliss, Richard, Strange Life, Sourcebook Project, 1976.
8. Michell & Rickard, Op cit. p. 50
9. Childress, David Hatcher, “Living Pterodactyls,” World Explorer, vol. I, no. 4, 1994.
10. Michell & Rickard, Op cit.
11. Childress, “Living Pterodactyls,” Op cit.
12. Kuhn, “Eskin Kuhn's Excellent Adventure,” About Paranormal Phenomena, 2007
13. Sanderson, Op cit.
14. The Shadowlands
15. Wagner, Stephen, “Did Pterosaurs Survive Extinction?” paranormal.about.com, 2007.
16. Childress, Op cit.
17. Coleman, Loren, “King Kong’s playmate: Kongamato,” Cryptomundo.com, 2007.
18. Wagner, Op cit.