METHODS

The hypothesis that a given petroglyph depicts a dinosaur makes four predictions: (1) the image is a single image, not a composite of separate images, (2) it depicts an animal, (3) its features cannot be reconciled with an interpretation that it depicts a member of the non-dinosaurian local fauna that was contemporaneous with its maker(s), (4) its features depict a specific, identifiable dinosaur, and (5) it is entirely human-made.

To test these predictions the four alleged dinosaur depictions were examined with the naked eye and with the aid of binoculars and telephoto lenses. Observations were made while the images were illuminated by direct and indirect sunlight and when they were in shadow. Accurate documentation and analysis of petroglyphs requires this level of observation and recording insofar as visibility varies considerably under changing light conditions, and it may be difficult if not impossible to perceive differences between natural and man-made manipulations of sandstone surfaces.