From the Saurians Introduction:
The scientists got it wrong. Not all the dinosaurs are extinct. In the late Jurassic Era, a species of raptor discovered the ability to communicate with each other through thoughts. Over the centuries, this evolved into a shared-mind consciousness which enabled the raptor brains to exceed the limits placed on the size of their brains. A civilization developed, based on a store of knowledge and the easy to hunt emerging mammals. Tools were developed, the megafauna tended, and species bred to enhance their individual natures. Key to their success was the Ytenn species discovering the ability to control lesser minds. No longer were the raptors hunted by T. Rex or other dinosaurs. Brontosauri were kept like cattle, used for their brute strength or raised for their meat.
The P'tor-ra dominated the landscape for a brief time, however. Just as they began to develop true societies and kingdoms that may have left fossil records, they discovered a massive comet about to smash into the planet. The P'tor-ra put all their efforts into finding away to escape the impending doom. Using controlled dinosaurs and burrowing mammals, massive caverns were tunneled deep underground for the P'tor-ra to hide in. each tunnel was covered with an immense capstone, then marked with a giant pyramid of stone -- perhaps the only structure that would survive the cataclysm and mark their resting place should other saurians seek them out after the cataclysm.
From the Humans Introduction:
The announcement of new chambers found beneath the burial chamber in the Pyramid of Khafre in Giza was met with much excitement. Early reports spoke of an early form of hieroglyphics as yet unknown to archaeologists and pictographs of an early Egyptian creation myth. Within a few days, however, the Egyptian Supreme Council of Antiquities announced the closing of the site to all but one team of renowned archaeologists. No further information about the chambers were released.
Inside the team discovered two rooms. The most interesting one was a circular chamber, uncommon in Egyptian construction, with the unusual hieroglyphs covering every surface and a massive stone circular slab set in the center of the room. The room was undoubtedly older than the Pyramid itself, but lack of material prevented any radio-isotope dating. The outer room seemed to be of later design, contemporary with the pyramids. It appeared to detail the discovery of the circular chamber and a translation of the strange writing within it. Those who have studied it have described the carvings as the "Myth of the P'tor-ra", that came before mankind.