2400 A.D.

Reptite Timeline

-Dinopolis is pulled to the Keystone T-2 to serve as a counter-balance for 
Chronopolis's being pulled back in time. 
-We may infer that with the Dragon God and Dinopolis suddenly disappearing, the 
Dragonian society may have undergone perilous times.

Keystone T-1

-In an experiment meant to conquer time, Chronopolis causes the Time Crash. The 
full effects of this Crash are unknown, and probably do not matter. 
-Lavos pulls Chronopolis back 10,000 years to 7600 B.C. in an attempt to
introduce a major influence in history to interrupt Crono's quest; FATE
realizes such and probably hereafter begins the plans for Records of FATE and
minimalization of historical influence. This event perpetually restarts the
timeline to 7600 B.C.; the new strain is known as Keystone T-2 and contains
every action of Crono coupled with the introduction of Chronopolis into the
past.

From: Chronology