For centuries reports of a large mystery cat have come out of the Sierra Madre Occidental range in northwestern Mexico. The Aztecs, who called it the cuitlamiztli, believed it to be a third species of felid, separate from the other native cats, the puma and the jaguar. It was thinner than the other cats, for one thing, and its ears were longer. The Spaniards, who noted its fierceness and its willingness to take on even armed men, gave it the name onza, after the Latin uncia (cheetah).

Though unrecognized by zoologists and little known to the larger world, its existence was taken for granted by locals. In the 1930s, an American hunting party seeking jaguars on La Silla Mountain treed an Onza and killed it. The hunters did not keep the remains, and later, when the guides told zoologists about it, they were met with disbelief. In the 1950s, however, Robert Marshall, who was researching a book on the Onza, interviewed them and conducted his own investigations in Mexico. Marshall’s book The Onza, which appeared in 1961, was little noticed.

In the 1980s, J. Richard Greenwell, secretary of the International Society of Cryptozoology, contacted Marshall, who gave him part of an Onza skull. A University of Arizona zoologist, E. Lendell Cockrum, directed them to two Sinaloa, Mexico, ranchers who had another skull. Yet another was located in the Academy of Natural Sciences in Philadelphia.

Then two deer hunters killed an Onza on the evening of January 1, 1986, in Sinaloa’s San Ignacio District. Greenwell was alerted, and soon afterward he and University of New Mexico mammalogist Troy Best took photographs of the body before dissecting it at the Regional Diagnostic Laboratory of Animal Pathology in Mazatlan. Greenwell would write that “the cat, a female, appeared to be as described by the native people”—in other words, long, thin, and large-eared.

It would be more than a decade before results of the many analyses on the remains were published. In 1998, the final test results were reported in the journal Cryptozoology: tissue samples from this Onza were not from a distinct species of cat but were indistinguishable from those of North American pumas.



The Encyclopedia of Loch Monsters,Sasquatch, Chupacabras, and Other Authentic Mysteries of Nature
Written by Loren Coleman and Jerome Clark – Copyright 1999 Loren Coleman and Jerome Clark