Lyric discussion by Counterclockwerk 

Cover art for Petrified Forest lyrics by Captain Beefheart and the Magic Band

Agree with poster above, Beefheart was an environmentalist, a poet with strong affinity with nature, this poem has a prophetic tone. Humans face fate of dinosaurs, man is extinct, love the image of petrified forest, literally "turned to stone", incidentally name of a painting I once saw by artist Max Ernst.