Just as a side note, if you're Vue users, you can make a couple of "key" prehistoric plants by modifying some standard Vue solid growth.

Imx3d made a great calamite (horsetail) using the Prehistoric Pine Tree. I did the same based on the work he did. You can see the results clearly on this image

http://www.renderosity.com/mod/gallery/index.php?image_id=2190427&user_id=457113&np&np

And I've made a fairly descent monkey puzzle tree using the Scots Pine. You can see that clearly in this one.

http://www.renderosity.com/mod/gallery/index.php?image_id=2124322&user_id=457113&np&np