In Chronopolis, a diagram supposedly depicting an Early Human and a Human is presented to contrast Lavos evolution. The alleged Early Human is shown with apelike features, even though Ayla is shown to be an upright homo sapiens in Chrono Trigger, along with her colleagues. What gives?
Chrono Cross establishes that early humans contacted the Frozen Flame around 3000000 B.C., and that Lavos evolved them to modern humans rapidly. These modern humans would later create the Kingdom of Zeal and modern civilization. The same quote that establishes the three-million year timeframe also speaks of the brains:
[Prisoner] When I was still human, I was locked up here, and I have been here ever since... This tower is a fortress belonging to the ancient Reptites... A symbol of revenge, brought against mankind by the Dragons... With the defeat of FATE, the seal has been broken and this tower has surfaced... In the eyes of the Dragons, we humans are the foes... A brain that has developed abnormally to 3 times the original size in the span of 3 million years... We humans have evolved at an enormous rate because of our contact with Lavos's flame... In a sense, mankind is Lavos's offspring... We humans are extraneous to this planet... Now... How will you fight, Serge...
There you have it; the brain and early human depicted in Chronopolis looks like a an Australopithecus human or Homo habilis, while Ayla, Kino, and the others are shown to be fully-formed humans in Chrono Trigger. One can also object to the brain comparison, since Ayla and her kind are also fully-formed humans intellectually.
Masato Kato worked on Chrono Trigger and Chrono Cross at the deepest stages of its development, precluding the possibility of making a mistake simply by forgetting Ayla's concept art and the status of humans in 65000000 B.C. This is probably just an accident by the field artists for the maps of Chrono Cross, not caught by Kato or the other higher-ups.
Other, Farfetched Theories
- Thought: Chronopolis got its evolutionary data only from the Dragonians after the Polis War, and in the Dragonian dimension, early humans looked like that (whereas in the Keystone dimension, Ayla and her friends are normal humans).
- Chrono'99: Chrono Cross is taking creative license. (Chrono Trigger could also retroactively be taking creative license, but this runs into problems with the drawing of Ayla at Lucca's house and the brain/cognition issue.)
- Chrono'99: Lavos's impact sent the Frozen Flame back in time to 68,000,000 B.C., preserving the three million year figure and allowing for Ayla and her kind to be evolved in time for Crono to meet them.
From: Plot Inconsistencies