Stones such as this one depict dinosaurs with incredible accuracy.  The details of the skin and dermal spines reinforce the fact that the artisans must have seen real live dinosaurs.  These stones pre-date many modern discoveries by scientists such as details like dermal spines and patterns on dinosaur skin, yet they depict these details with amazing accuracy.

Modern discoveries of the Ica stones (and others like them) are made oftentimes alongside pre-Columbian mummies.  These graves oftentimes include various clothing items, vases, toys, and other items one would expect to find in the burial site of an individual buried in their time period.  The stones oftentimes have similar imageries as those found on the clothing or tapestries..

Many of the stones depict animal life which is consistent with other artifacts in the surrounding area such as the Nazca Lines.  Here the monkey image resembles that of the monkey image found in the Nazca Lines.  Likewise images of hummingbirds, condors, dogs, humans, and many other things are found on the stones.

As with the Styracosaurus, this is a clear graphical representation of a human riding upon the back of a Triceratops.  The classic frills and three horns we have seen in modern artwork depicting this species is reflected in the art of pre-Columbian peoples.  Dennis Swift's book delves into the evidences which support the authenticity of these stones, which is critical given that the clarity of the images and the obvious logical historical implications are without question on these amazing specimens.

Just as clearly as the image of a monkey can be seen, here is the image of a man and a Styracosaurus or similar species.  This stone is crafted of the same materials, in the same style, and found alongside the same artifacts as those depicting animals seen in modern life such as the monkey above.  Without question, the individual who carved this stone must have seen a live specimen to create such a detailed image.