Organism: Tenku
Ancestor: Anku
Selective Pressure: Increasing migration through lower-ammonia environments.
Mutation: Development of airborne chemical markers and gymnosperms.
The wandering Anku of the previous Epoch achieved great success, but they were individual actors that reproduced with a waterborne sporophyte cycle. As beautiful as translucent baby floating mushroom trees rising out of the water might be, it was a serious limitation in the reproduction cycle. The main morphological adaptation of the Tenku was the development of a delivery system for nutrient-bearing gymnosperms that could implant in the ground with only moderate levels of moisture. The Tenku developed long, filamentous, seed-bearing pod-strands trailing down from the main canopy, which would incrementally burst during different periods in the float migration cycle, seeding the land with thousands of new Tenku as they travel.
The second, invisible adaptation is that other filamentous pods burst with various airborne chemical factors, which either signal the beginning of a reproduction cycle or a migration cycle. This is then propagated throughout the entire Tenku forest which then seeds or uproots and migrates, or both, as one. This is not a hive mind or even a neural structure, simply a collective chemically-propagated tropic response. (An analogue might be the lytic and lysogenic cycles of certain earthborne bacteria.) Tenkus now tend to migrate in fixed patterns, seeding the ground with discarded seed pods and desiccated corpses to build up the layers of humus necessary for future generations of larger Tonudae forests.