James Gurney
Footprint Alphabet  1992

On the lost island, Dinosaurs have languages of their own that are often unintelligible to humans.  They
communicate effectively in written form, however, through the use of a footprint alphabet.  These calligraphic
imprints have evolved from earlier times when messages left in the form of tracks on muddy riverbanks conveyed
secret messages.

Illustration for Dinotopia: A Land Apart from Time
Rubber stamp on board

Link to image of plaque at Norman Rockwell Museum