An interesting fact that I learned from the book Metazoa is that biological diversity was greater in the seas than on land, until about 130 million years ago, and then the explosion of diversity on land, at that time and still now, was because of a feedback loop that developed between plants and insects, with the insects allowing greater specialization among the plants, and the greater diversity among plants allowing greater diversity among insects. This was a true feedback loop, in that it would be impossible to say what the starting point was, the insects or the plants.
Your dates are off by 100 million years. You're confusing the late Paleozoic for the late Mesozoic. Trees came first, the explosion of land-based bio-diversity happened more than 100 million years later.
Well i think invented is probably the wrong word moulded is probably better when you consider the fact that trees could be hundreds of years old before humanity proliferated and destroyed so many forests in last 1-200 years. It is not out of the question that animals could have evolved to serve trees as a 2-300 year old tree could see 100 generations of an animal
> Animals are something invented by plants to move seeds around. An extremely yang solution to a peculiar problem which they faced. (Terence McKenna)