The T. rex on some variants of the poster, as well as the DVD cover and menu screen is actually a toy model by the French model company Papo, slightly touched up with Photoshop. Another poster features an old robotic T. rex made by the now defunct Dinamation company, with spikes edited onto its head. Other creatures on the posters likewise come from other sources, they aren't from the actual movie.
At 1:27:55 the rolling end credits include "THE PRODUCERS WISH TO THANK.... THE CITY OF SHARMAN [sic], TEXAS". A Google search confirms the spelling of all the other locations in Texas but the closest to "Sharman" is "Sherman".