I never knew what the song referred to until I saw the “next exit Tucumcari” sign, and as it was late, I just had to find a hotel there.
https://www.youtube.com/watch?v=CAT3BXzVTME
The eocine to miocene sedimentary rocks of the Calvert Formation in Maryland (same age range as the tree parts in this article plus or minus) have fossil pollens and tree parts of maples, oaks and other species that are pretty close to temperate forests of today. It blows my mind, that if we landed in a temperate forest 20 or 40 million years ago we might be familiar with the scenery, but not even primates would be around yet.
I took a palynology course getting my BS in Geology in ‘89 at OSU. Never cared much for paleontology but LOVED the fossil pollens, many of them gymnosperms. So familiar yet so distant. Palynology is an incredible way of dating events, whether tens of millions or thousands of years old.