In the early exploration days, petroleum geologists were required to take field trips to inspect, map and collect geological data in remote locations, sometimes inaccessible except by foot, horse, mule or boat. Geological publications and maps of these hard-to-reach regions were almost non-existent, and the first geologists had to start from scratch, without any of the geological information that present-day geologists take for granted. They faced hazardous and unsafe situations, including heavy rains, flash floods, rockfalls, landslides, sunstrokes, mosquito bites, venomous snakes and spiders, attacks from natives and wild animals, and endemic diseases such as malaria and yellow fever, so vividly described in the 1960 book, “The First Big Oil Hunt: Venezuela, 1911-1916.” It contains a fascinating visual and material resources by the American geologist Ralph Arnold and other colleagues. Anyone interested in the history of the oil exploration rush and pioneering field work in Venezuela during the early years of the 20th century must read it.
Our story here is about a strange encounter with an enigmatic creature between 1917 and 1920 – the precise date is unknown – during a geological fieldwork expedition for oil exploration in western Venezuela, close to the Colombian border. The encounter was years later revealed to be one of the most notorious scientific frauds, comparable with the Piltdown Man hoax, as meticulously documented by the Venezuelan scientific researchers Bernardo Urbani and Angel Viloria in their 2008 book, “Ameranthropoides loysi Montandon 1929: The History of a Primatological Fraud.”
Explorers in a Challenging Territory
One of the regions in Venezuela that was first explored for oil during the early years of the 20th century was the Catatumbo, a basin that straddles the border between Venezuela and Colombia, which in fact is the southern edge of the Maracaibo Basin, one of the world’s most prolific hydrocarbon provinces. The Maracaibo-Catatumbo Basin is bounded by the Perijá Range and the Santander Massif on the west and the Mérida Andes to the southeast that meet to form a “Y.” The convergence to the south of these two mountain ranges marks the southern end of the Maracaibo-Catatumbo Basin. This region was considered to have a high oil potential because of the abundant oil and tar seeps that had been described at the surface, which were locally called “mene.” Some local place names were given because of the presence of petroleum at the surface, such as “Petrólea” in Colombia and “La Alquitrana” (“tar” in English) in Venezuela.
The oil seeps at the Colombia-Venezuela border were well known by the indigenous population, the Motilone Indians – a name that comes from the Spanish word “motilar” meaning “to cut or shave hair,” but the Motilone call themselves “Bari,” which means “we the people.” The Bari Motilone were making use of the oil for medicinal and lighting purposes. The occurrence of oil seeps in the Catatumbo region was also recognized by the pioneer explorers during the 18th century while searching for rubber and quinine, as well as the Capuchin missionaries eager to evangelize the isolated natives.
The region was known for the presence of the Bari Motilone, a tribe legendary in the Americas for its fierce opposition to intruders. Their active defense of their right to self-determination and preservation of their identity and territory left this region virtually unexplored by outsiders for almost 400 years. The Bari Motilone’s traditional way of life was intact and based primarily on agriculture and fishing, with hunting and gathering on a smaller scale. They lived in thatch-roofed communal huts and their only weapon was the bow and wooden arrows. They were famous for their marksmanship, their ability to drive an unfeathered arrow clean through a man at 230 feet. The arrows were not poisoned, but the barbs were so grimy that in some instances they caused the wounds to become infected, which in a few days could lead to death.
When the first geological expeditions in the early 20th century entered Bari Motilone territory, they were shot at. Geological camps were built to protect the explorers from all the dangers of the jungle by clearing a large area of forested land. In the center of this clearing, tents were erected and a walled house was constructed. The clearings were protected by a barricade of palm fronds, brush and other materials from jungle, allowing free movement within, but preventing possible observation by the Indians. The Bari Motilone attacks on geological camps and personnel in the jungle were greatly feared. Every expedition member had either a revolver or a rifle. For defense, it was necessary to employ armed guards who were posted nightly in relays. Their night vision was aided by kerosene lamps located at strategic points. The Motilone attackers started by shooting arrows into the camp, and when the arrows started flying and the outsiders hid for cover, the Motilone would creep into the camp and gather any metallic objects they could find, such as machetes, axes, cans and safety helmets. Many in the expeditionary forces were wounded by Motilone arrows and some were killed; numerous Bari Motilone were also killed during these raids.
First Exploration Activities in Catatumbo
The first oil activities in the Catatumbo region started in Colombian territory in 1905 when General Virgilio Barco obtained from a grateful Colombian government a 50-year concession for oil exploitation and refining, covering a large area in the Norte de Santander Department, adjoining Venezuela. A mule trail and a small still for oil refining were built within the “Barco Concession.” Oil was mined at “Petrólea,” a surface asymmetric anticline where – according to early reports -- the principal oil producing horizon was a “petroliferous black shale and limestone of Late Cretaceous age, which wherever found in this region, appears to be more or less petroliferous.” This formation appeared to be commonly impregnated with oil, filling fractures, vugs and fossils, suggesting the oil was indigenous. This “petroliferous black shale and limestone” was later known in the petroleum geology literature as La Luna Formation, a world-class source rock sequence.
Formal oil exploration activity in the Catatumbo portion of Venezuela, or southern end of the Maracaibo Basin, started in January 1907 by the awarding for 50 years of a 20,000-square kilometers concession, partially covering the District of Colon in the state of Zulia to Andrés Jorge Vigas, a Venezuelan lawyer, journalist, businessman and politician. Under Venezuelan legislation, the concessionaire had the right to do as he liked in the forest found on wild and public lands covered by the concession and to create the necessary infrastructure for its oil operations. The “Vigas Concession” titleholder was contractually committed to begin petroleum exploitation within four years from the date of the contract signature, with an optional extension of four more years to fulfill the commitment. There was no drilling at all, the venture did not yield the expected outcomes, and in 1913 Vigas sold the concession to the Colon Development Company Ltd., a subsidiary of the Royal Dutch Shell Group.
In 1913, two geologists sent by the Colon Development Co. to the “Vigas Concession” were attacked by the Bari Motilone and driven out. As a result of this hostile encounter, it was not until early 1914 that a geological exploration could be started in depth by three experienced geologists employed by the Caribbean Petroleum Co., a Royal Dutch Shell company that provided all the technical services to the Shell affiliates in Venezuela, including laboratory facilities and regional geology.
These three geologists were sent, with a strong escort, for topographical surveys, geological mapping and oil prospecting in a sparsely inhabited and little-explored region bordering Colombia. Fieldwork activity in this dense tropical rainforest consisted of detailed mapping of surface anticlines, locating oil seeps and outlining the regional stratigraphy, basically studied along riverbanks. After three months of pioneering reconnaissance work in the dense jungle, they discovered two large surface anticlines: the Tarra Anticline, in an area with abundant oil seeps and hot water springs, neighboring the Tarra River, a tributary of the Catatumbo River; and a prominent asymmetric surface anticline straddling Venezuela and Colombia, cut and crossed by the Rio de Oro, the river marking the boundary between the two countries.
Although the Tarra structure offered better prospects than the Rio de Oro Anticline, the Colon Development Co. decided to drill the first well on the Rio de Oro Anticline, due to easier access for material transport. The well pad was located on the Rio de Oro left bank, and the drilling and camp equipment were shipped by canoes from Maracaibo Lake upstream along the Catatumbo and the Rio de Oro rivers. The camp was set up in June 1914, one month before World War I broke out, which resulted in a delay of the drilling start. The Rio de Oro well was spudded in late 1914 but was suspended at a depth of 700 feet after experiencing difficulties with the drilling equipment and disputes among the drillers. Finally, overcoming all types of problems, drilling was resumed in 1915. At 1,000-foot depth the well blew out and tested some 200 barrels per day of light gravity oil from a sandstone package of Paleogene age. The Rio de Oro well was set on production and a very rudimentary, small oil refinery was constructed, which provided gasoline for the motorboats.
Simultaneous to the operations in Rio de Oro, a five-mile tramway to transport the drilling equipment was laid from a landing spot in the Tarra River to the El Cubo camp, located at the northern plunging axis of the Tarra Anticline, some 11 miles from the Colombian border, where the first Tarra well was drilled in 1916. The well flowed oil naturally while drilling another Paleogene sandstone sequence at 875 feet. After it was eventually completed, the well produced up to 1,230 barrels per day of 22-degree API crude.
The Monkey’s Photo
After the encouraging drilling results in the Rio de Oro and Tarra wells, a party of Venezuelan engineers and workers employed by the Caribbean Petroleum Co., led by the 25-year-old Swiss geologist François de Loys, were commissioned in 1917 to conduct a topographic mapping and a more detailed geological reconnaissance of the Tarra Anticline and neighboring structures, in the heart of the Bari Motilone territory.
The geological mission was based in El Cubo camp. The precarious conditions of that camp made a great impression on the young Swiss, who for the first time had to suffer the trials of warm temperatures, dense jungle, illnesses and the constant siege of those “wild Indians, invisible, silent, and fiercer than the Germans,” according to his own words. Departing from El Cubo, they organized fluvial and terrestrial reconnaissance trips, for which it was necessary to cut trails and take great precautions, being armed at all times. According to the chronicles published by de Loys himself in 1929 in The Illustrated London News and The Washington Post (although not always consistent with each other), during one of those trips, the date of which is uncertain, at a bend of a minor tributary of the Tarra River, a noise broke out in the forest. He initially thought that they were again being attacked by the Bari Motilone, but suddenly were violently approached by “two huge animals with dark, hairy bodies.” The animals “standing up clumsily, shaking with rage, grunting and roaring” attacked the men by throwing branches and their excrement. The men had no choice other than shooting, and they killed one of the two animals at very close range. The other animal, unfortunately wounded, managed to escape and disappear in the impenetrable jungle.
The animal shot dead was examined, having been placed in a sitting position on a box of unknown size, supported by a stick under the chin and immediately photographed, as can be observed in the photo taken from the front and published in the 1929 chronicles by de Loys. The Swiss geologist alleged that the animal measured 62 inches in height and its weight was estimated over “eight stone” (50 kilograms, or 112 pounds). At first examination it was found that the specimen was that of an ape of uncommon size whose features were entirely different from those of the species already known to inhabit the country. According to de Loys, the ape’s skin was removed afterwards, and its skull and jaw were cleaned and preserved, but were lost entirely, due to the hardships met by the party on the long journey back across the rainforest. The geological expedition suffered greatly due to disease and skirmishes with natives: of the 20 members of de Loys’ original group, only four survived. Finally, the only evidence that remained of the animal was the photograph. It was filed away by de Loys with his geological reports and notebooks on the expedition and went unnoticed for years.
More than 10 years after the alleged encounter, George Montandon, a Swiss physician with a particular interest in anthropology, and strongly influenced by racist ideas of human evolution, discovered the photo of the dead animal while looking for information in the notebooks of his friend François de Loys about South America’s native tribes. Based solely on this photo, Montandon authored a 1929 series of scientific and popular papers in French journals in which the animal’s photo was published and described as a unique anthropological and zoological discovery. This was founded on the animal’s size, absence of tail, hyper-development of the clitoris and the number of teeth. Montandon proposed “Ameranthropoides loysi” as the scientific name for this “new American ape” in honor of its discoverer. Montandon went further and presented the ape as clear evidence of polygenism, an old, eccentric and racist evolutionary theory supported by some scientists during the 19th century. It suggested that the human races evolved independently from separate species of apes, rather than sharing a common ancestor. The discovery of this primate was interpreted by Montandon as the missing link between Native Americans and apes.
Immediately after the publicity of the “new American ape,” a controversy within the European anthropology and zoology communities emerged. Many published versions of the photo were also modified or the image itself was cropped, magnifying the impression left by the ape. The fact that no part of the specimen had been retained was the main shortcoming of the scientific debate. After careful analysis of the photograph, which did not clearly indicate the creature’s size, some scientists rapidly claimed it was no mysterious ape, but a normal spider monkey quite common in the Catatumbo region, qualifying the case as a hoax. Others maintained that the animal might exist and accepted that the primate could be a new species but rejected its relationship with human origin in America. Some fully supported Montandon’s premises. Attempting to solve the controversy, field searches were organized to the Catatumbo region, but the mysterious ape was never found.
The controversy continued along into the 20th century with the ape story and the photo becoming very popular in pseudoscientific books and TV documentaries on monsters and mysteries. The controversy was also discussed in the cryptozoology literature as an unresolved case.
The definitive clue that the Ameranthropoides loysi story was a prank and a complete hoax comes from a letter by Enrique Tejera, published in 1962 in El Universal, a Caracas newspaper. Tejera was a Venezuelan doctor who had known the Swiss geologist during their time working together for the Caribbean Petroleum Co., when Tejera was hired to work as the medical doctor in the oil company camps in the southern Maracaibo-Catatumbo basin.
In his writing, Tejera provided interesting information about de Loys’ joking personality and the real story of the “American anthropoid ape discovery.” The story started with a photograph, clearly manipulated, of a common spider monkey, the Ateles belzebuth, locally known as “marimonda.” According to Tejera, the Swiss geologist owned a pet spider monkey that he adopted in the jungle and called “hombre-mono” (monkey-man), which was none other than the dead animal that appeared in the famous photograph. The monkey’s photo with a wide river and a banana plantation in the background had been taken just where de Loys’ pet monkey had died, precisely in an oil exploration camp of the Caribbean Petroleum Co. in the southern Maracaibo basin. This was the place where Tejera witnessed several people preparing to take a doctored picture of the dead spider monkey seated on a box and with no tail, since it had been cut off. Case closed!
Tejera made it very clear how the fraud was created. The monkey’s photo had been taken by a prankster petroleum geologist, then landed in the hands of a fraudulent and racist anthropologist. Both agreed to elaborate and publish a false story, which was then used to support an outdated theory for human origins.
Enrique Tejera, who had graduated in medicine at the age of 18, became a worldwide recognized expert in tropical medicine and epidemiology. During the 1930s and ‘40s he was appointed minister of health, minister of education and president of the Red Cross in Venezuela. He died in Caracas in 1980 at the age of 82. However, the two main actors who elaborated the fraud and originated the controversy did not enjoy a good ending. In 1920 Francois de Loys left Venezuela to work as a field petroleum geologist in Algeria, Texas, and finally in Iraq, where he contracted syphilis. Weak and seriously ill, he returned to Switzerland where he died in 1935 at the age of 43. Meanwhile, Georges Montandon continued to defend the theory of polygenism vigorously. He became a virulent anti-Semite and an active collaborator with the Nazis in World War II during the German occupation of France. He apparently was killed in 1944 by the French Resistance.