I decided I'll start putting together library of 3d trees and plants that were probable trough out the dinosaur era. I want to start using these plants and trees in my illustrative work as to improve the look and feel of my creations and give them more "authentic" appearance. I kind of got tired of composing dinosaurs within environments constructed out of my own photographs of modern forests, trees and plants.
I've started this quest with Sequoia. Magnificent tree that exists today and is naturally growing only on the western slopes of the Sierra Nevada Mountains of California. Most of these monumental trees (about 95%) were obliterated during logging in late 19th and early 20th century.
Hopefully we will preserve and rebuild at least part of these forests that were there before cos it is heart wrenching looking at these gentle giants fade away like so.
Anyway, to go back to the topic. I own Vue 8 Infinite software that contains comprehensive library of trees and plants.  
There is one Sequoia tree there but it just doesn't look good if you need to render it in any proximity to the camera. It could work well for distant shots of complete forests on vast terrain.
For my work I need trees and plants that can bee set closer to and around subjects of the illustrations, both foreground and background.  
Bellow you can see the rendered tree. This is the alpha tree. It is built in pieces so I can easily rebuild it using its parts to form more unique trees from it. I also made 3 varied tree trunk textures. This way I can avoid having obvious repetitive elements within one or series of illustrations.

Check out my Sequoia and couple of "making of" shots here: [link]