The Archeopteris Tree

My scanner pretty much mangled this scan but then I don't usually have much success scanning in sketches. This is a detail of a print I'm working on for next summer's show. I had the idea a few years ago and never really saw it to fruition. The Archeopteris Tree was a very prolific progymnosperm (before seeds bearing plants)and one of the very first trees. It grew in a large swampy area near the steppes of the Blue Ridge Mountain Range back when they were the size of the Himilayas of today. Archeopteris had the habit of shedding leaves and limbs on its growth cycle up and out. Placoderms or plated fish ruled the seas at the time and had voracious appetites. An organism was discovered from this period that was still fish like but instead of fins had four limbs with 8 fingers attatched to the ends. The joints were too weak to support the weight of the animal but would be perfect for brushing aside vegetation and wriggling through brackish water. I can't remember the name of said animal off the top of my head but the theory goes that "8-toes" sought the refuge of Archeopteris swamps in hopes of escaping the Placoderms. Perhaps this environment harbored and encouraged the first steps towards land dwelling vertibrates. I am drawing up plans to print a large scale woodblock print in the style of old European block print texts with the image of a great Archeopteris standing in brackish water. Amidst the shed limbs of vegetation, a few "8-toes" hang out under the trunk of the tree while Placoderms patrol the outlaying areas. To help the "old world" feel of the image, I'm drawing a boarder of Archeopteris leaves and 4 corner images of Archeopteris spore. Now if I only knew what Archeopteris spore looked like.....