See photos on my website: http://MexicanArchaeology.tripod.com
Most of these were discovered by a German Archaeologist between 1922 and 1954. Many are now on display in a museum in Acambaro, Guanajuato, Mexico. Carbon dating has been done in 3 separate locations. All agree on the approximate time of modeling.
How is this possible when we didn't know what dinosaurs looked like until about 200 years ago?