Several years ago I was studying the coastal redwoods in California, unfortunately I didn't save where I read it, but apparently, coastal redwoods used to stretch down the entire west coast of North America all the way down to Baja California. Redwoods can no longer live there because the climate is not suitable. They now only live in a small swath of land along the coast from north of San Francisco to about 100 miles south of the Oregon border.
Today, the coastal redwoods are clearly deep in the process of going extinct. But, it said that the coastline used to go from east to west, rather than north/south like it does now, and the climate was much more like the northern California coast is today. So it was ideal for coastal redwoods.
Now I don't know if the trunks they found were petrified or what, but in my thinking it had to be a much more recent event than 800,000 years ago or the evidence would have not survived. Besides, Charles Hapgood, the originator of the pole shift theory said they occurred much more recent than that. I'll need to pull the book out to find his dates. Furthermore, he never speculated that the poles reversed, they just shifted to a new location. And in his book he shows the former locations of the poles based on his research. It's been a good 15 years or more since I read it, but I'd recommend the book to anyone interested in this subject.
Earth's Shifting Crust : Hapgood,Charles H. : Free Download, Borrow, and Streaming : Internet Archive