Oh, man, this gets so much wrong. Sentient life did not evolve 600 million years ago; that was roughly the time that true multicellularity arose. Unless you consider something spongelike to be sentient, it doesn’t work.
Intelligent life did not first evolve 2.5 million years ago. Animal intelligence is something that has to be measured on a continuum. Molluscs are intelligent. It’s just not the same kind or degree of intelligence that tool-using humans have.
Intelligent life hasn’t evolved in Texas yet.