Prototaxites - Ecological Context

Ecological Context

This organism would have been the tallest living thing in its day by far; the plant Cooksonia (pictured in navigational box below) only reached 1 m, and itself towered over the "moss forests"; invertebrates were the only other land-dwelling life. Prototaxites became extinct as shrubs and vascular trees rose to prominence. The organism could have used its raised platform for spore dispersal, or, if Prototaxites really did form leaves, in competition for light. The University of Chicago research team has it reconstructed as a branchless, columnal structure. The presence of bio-molecules often associated with the algae may suggest that the organism was covered by symbiotic (or parasitic) algae (making it in essence a huge lichen), or even that it was an alga itself.

Prototaxites mycelia (strands) have been fossilised invading the tissue of vascular plants; in turn, there is evidence of animals inhabiting Prototaxites: mazes of tubes have been found within some specimens, with the fungus re-growing into the voids, leading to speculation that the organisms' extinction may have been caused by such activity; however, evidence of arthropod borings in Prototaxites has been found from the early and late Devonian, suggesting the organism survived the duress of boring for many millions of years. Intriguingly, Prototaxites is bored long before plants developed a structurally equivalent woody stem, and it is possible that the borers transferred to plants when these evolved.