Ayla (エイラ, Eira?), is the chief of the Ioka tribe in 65,000,000 B.C. Her people are in constant war against the Reptites: an evolved, intelligent race of reptiles. She is characterized as fiercely courageous, decisively confident, and morally pure. After Lavos hits the planet, dust blasts into the atmosphere and blocks out the sun. This causes an ice age and the extinction of the Reptites; Ayla subsequently retires from her duties as chief. Ayla cannot use magic because she was born before humans became genetically capable of doing so (as further explained through human evolution in Chrono Cross). She relies on unarmed combat and physical prowess in battle. Interestingly, in the original Japanese version, she makes a bisexual comment upon meeting the party (which was censored to “respect” in the English release).

Ayla's name could be an allusion to Jean Auel's Earth's Children series, the protagonist of which is a tall, blonde-haired, green-eyed, prehistoric girl named Ayla. It could also refer to the tayra (Eira barbara), as her outfit contains a furry tail akin to the one of this animal. In the ending cutscene of the PlayStation port of Chrono Trigger, Ayla is seen brashly forcing engagement on Kino, her suitor and one of Marle's ancestors. This displays her confident and strong-willed personality. In Chrono Cross, Ayla does not make an appearance; however, a young girl from prehistoric times named Leah bears a striking resemblance to her in manner and appearance. She also says to Serge at the end of the game that she will name her child “Ayla”, a name meaning “New song of land” according to her.