In October/November 1924, a Dr Samuel Hubbard (not the well known entomologist, S Hubbard Scudder, 1837-1911), curator of archaeology for the Oakland (California) Museum of Natural History and working for the Doheny Scientific Expedition, found pictograms on the cliff walls of Hava Supai (or Havasupai) Canyon (Arizona, USA). Most of the pictograms consist of human figures and well known local fauna, including ibex, horse, deer and birds; remarkably, though, one depiction is said to resemble a Tyrannosaurus Rex; according to some accounts, the beast is poised ready to eat a human, while according to others, fossilised dinosaur footprints were found nearby, whilst it has also been claimed that the pictograms are covered by a ferruginous patina. Some accounts change the details. The expedition is sometimes said to have taken place in 1894-5 (muddling an account in which E L Doheny, who funded the expedition, first visited the Canyon) and there are alleged quotes from Hubbard:
Taken all in all, the proportions are good… [The dinosaur is] depicted in the attitude in which man would be most likely to see it: reared on its hind legs, balancing with the long tail, either feeding or in fighting position, possibly defending itself against a party of men.
These sorts of claims are easy to deal with. For a start, the picture of the pictograph says a great deal. Firstly, it is reproduced without context; we are not shown other figures from the same rock-face or others from the canyon, against which it might be possible to evaluate it. Is the picture even reproduced the right way up? Even allowing that it is, what does it show? There is an outline that somewhat resembles a Tyrannosaurus, but there are problems with the tail, the length of the neck and the lack of front legs. The idea that Tyrannosaurs dragged their tails along the ground may have been current in the 1920s, but it has not been believed for many years now, so if the pictogram really does show an eyewitness depiction of a giant meat-eating dinosaur, we need to explain why it is depicted in an incorrect position. A more economical hypothesis is that the pictogram shows something else that bears a slight resemblance to the way Tyrannosaurs were once thought to have looked. It is certainly not evidence that the artist had seen a living Tyrannosaur.