As of 06:31 AM MDT on Monday, October 27, 2025, the tale of the De Loys ape remains a captivating enigma in the annals of cryptozoology, blending adventure, controversy, and folklore. In 1929, a photograph surfaced purporting to depict an unknown primate, dubbed “De Loys’s ape” or Ameranthropoides loysi, allegedly encountered by Swiss geologist François de Loys during a 1917 expedition west of Lake Maracaibo near the Colombian-Venezuelan border. The image showed a tailless, bipedal creature propped against a crate, its body slumped as if shot, sparking claims of a “missing link” between humans and apes in South America. De Loys recounted how, after three grueling years prospecting for oil, his decimated crew faced two “ape-men” that charged their Tara River camp, hurling sticks, rocks, and feces before he and his men killed a female and wounded a male. Though the carcass was photographed and partially preserved, it was abandoned, leaving only the photo as evidence. Initially hailed as a scientific breakthrough by French anthropologist George Montandon, the consensus today leans toward a hoax involving a manipulated spider monkey. Yet, local tales of the Salvaje, a hairy, human-like figure said to kidnap and eat humans, keep the mystery alive. Was this a case of an abnormally large primate, or a glimpse of a lost species? This article explores the expedition, evidence, debunking, and the enduring allure of the unknown.
The 1917 Expedition: A Descent into the Jungle
François de Loys (1892–1935), a Swiss geologist and petroleum engineer, led a small expedition into the wilds west of Lake Maracaibo from 1917 to 1920, commissioned by a Venezuelan oil company to search for petroleum in the Orinoco Basin. The region, a dense rainforest near the Venezuela-Colombia border, was fraught with danger—disease like yellow fever and malaria claimed most of the crew, reducing it to de Loys and three others by 1920. Encounters with hostile indigenous groups, possibly the Yanomami, added to the toll, with reports of skirmishes and ambushes.
By the expedition’s third year, the survivors had camped along the Tara River (likely a Catatumbo tributary) in Zulia state, Venezuela. De Loys later described an astonishing event in 1917: while resting, two bipedal, monkey-like creatures emerged from the undergrowth, standing about 1.5 meters tall with hairless faces and chests, long arms, and no visible tail. Waving branches and screaming, they threw sticks, rocks, and feces at the camp—a behavior echoing chimpanzee aggression but unusual for New World monkeys. In a panicked response, de Loys and two companions fired their rifles, killing the female and wounding the male, which limped into the brush and vanished.
Struck by the creature’s size, de Loys attempted to preserve the carcass, skinning it, boiling the skull, and storing the head and paws in formalin. However, logistical challenges and disease forced him to abandon the specimens during the retreat. Before doing so, he propped the body upright against a crate, measured it, and captured a single photograph with a Kodak camera, tucking it into his journal where it lay forgotten for over a decade. This image resurfaced in 1929 when de Loys shared it with Montandon, setting the stage for a scientific sensation.
Publication and Initial Reception
In 1929, Montandon published the photograph and de Loys’s account in Illustrated London News and his book L’Homme de la Selva, christening the creature Ameranthropoides loysi (“American man-like”). He portrayed it as a 1.57-meter-tall “missing link,” lacking a tail and exhibiting human-like posture, aligning with his polygenist theories of multiple human origins distinct from African or Asian lineages. The 1920s, rife with eugenics and fascination with human evolution, provided fertile ground for such claims. De Loys, by then a recluse in Switzerland, died in 1935, adding to the narrative’s mystique. The story spread globally, inspiring expeditions, including Montandon’s 1937 venture, and fueling debates that paralleled the era’s pseudoscientific fervor.
Scientific Debunking: A Spider Monkey Hoax
By the 1970s, evidence mounted that the “De Loys ape” was a hoax involving a spider monkey (Ateles belzebuth), South America’s largest New World primate, which can reach 1.5 meters including its tail. Key points include:
Tail Manipulation: The photo lacks a tail, but spider monkeys have prehensile tails up to 90 cm long. De Loys noted the tail was “damaged” and removed during skinning, yet forensic analysis by Bernard Heuvelmans (1969) and later experts confirmed it was likely excised to mimic a human-like form.
Propped Pose: The body was upright on a box with a stick supporting the head, a taxidermy trick to suggest bipedalism. Spider monkeys, though arboreal and quadrupedal, can stand briefly, and the photo’s angle enhances this illusion.
Size Discrepancy: De Loys claimed a height of 1.57 meters, but the image depicts a smaller specimen, consistent with a juvenile spider monkey. Montandon’s measurements appear exaggerated for effect.
Behavioral Mismatch: The aggressive display matches spider monkey behavior when threatened, but de Loys amplified it to fit a “missing link” narrative.
Heuvelmans, initially supportive in On the Track of Unknown Animals (1958), later conceded the hoax after re-examination. In 2016, David Bressan’s Forbes article suggested de Loys’s motives—possibly publicity or Montandon’s eugenics agenda—drove the fabrication. High-resolution scans of the photo, now in Montandon’s collection at the University of Geneva, reveal clear manipulation, cementing the spider monkey conclusion.
Local Folklore: The Salvaje and South American Cryptids
The De Loys tale resonates with South American folklore, particularly in the Orinoco Basin, where indigenous groups like the Yanomami recount the Salvaje or Mapinguari—a hairy, human-like creature rumored to kidnap women, build huts, and eat human flesh. These legends, akin to Bigfoot or Yeti stories, may stem from misidentified large primates or cultural memories of extinct megafauna like ground sloths. The woolly spider monkey (Brachyteles arachnoides), at 1.4 meters with a 75 cm tail, is a likely candidate for such tales, its bipedal posturing and vocalizations fueling myths.
No fossil evidence supports a relict hominid in the region; South America’s primates are New World monkeys, diverging from Old World apes 40 million years ago, with no Homo species beyond modern humans. The Salvaje, like the De Loys ape, likely reflects exaggerated sightings, paralleling the ancient carving’s speculative rifle or the Eltanin Antenna’s sponge misidentification.
Legacy and Cultural Impact
The De Loys ape endures as a cryptozoology icon, featured in Loren Coleman’s Cryptozoology A to Z (1999) and MonsterQuest episodes. It influenced pseudoscientific pursuits, including Nazi expeditions for “Aryan” origins, and thrives in online forums. Debunked yet captivating, it mirrors the Tasmanian tiger’s lingering allure or the black seadevil’s rarity, highlighting humanity’s fascination with the unknown.
Conclusion: Hoax or Harbinger?
The De Loys ape, photographed in 1917 and later exposed, was likely a manipulated spider monkey, a hoax amplified by Montandon’s agenda. The Salvaje folklore adds cultural richness, but evidence favors natural explanations over lost primates. Like the Coso Artifact or Ashley Phosphate Beds, it cautions against selective interpretation, advocating for rigorous science. Yet, its story persists, a reminder that the jungle’s shadows may still conceal mysteries—monkey or myth.
