‘Mystery big cats’ in the Peruvian Amazon: morphometrics solve a cryptozoological mystery

Two big cat skulls procured from hunters of Yanachaga National Park, Peru, were reported as those of cats informally dubbed the ‘striped tiger’ and ‘anomalous jaguar’. Observations suggested that both skulls were distinct from those of jaguars, associated descriptions of integument did not conform to this species, and it has been implied that both represent members of one or two novel species. We sought to resolve the identity of the skulls using morphometrics. DNA could not be retrieved since both had been boiled as part of the defleshing process. We took 36 cranial and 13 mandibular measurements and added them to a database incorporating nearly 300 specimens of over 30 felid species. Linear discriminant analysis resolved both specimens as part of Panthera onca with high probabilities for cranial and mandibular datasets. Furthermore, the specimens exhibit characters typical of jaguars. If the descriptions of their patterning and pigmentation are accurate, we assume that both individuals were aberrant.