by Joanna F. Woolley

Figure 12. Lycopod bases (the small one is immature) with branching tree root stigmaria, Museum der Geol. Landesanstalt in Berlin. (From Gotham, W. and Weyland, H., Lehrbuch der Palaobotanik, Akademie Verlag, Berlin, p. 145, 1964.)

New fossil and field evidence relating to the structure of the root system of lycopods, the dominant vegetation of Upper Carboniferous strata, are presented and critically examined. Neither the elastic and partially hollow nature of the lycopod root structure, their inferred geometry throughout early ontological development, nor other evidence support the prevailing paradigm that the coal measures formed in a terrestrial swamp environment. Rather, they favour the floating forest or silvomarine hypothesis of Kuntze regarding the formation of Paleozoic coal layers.

Are lycopods structured for water immersion?

Part 1 of this paper traced how researchers have traditionally thought the Paleozoic coal deposits of the northern hemisphere formed in swamps.1 It described how in recent decades there has arisen renewed interest in an alternate view—i.e. that they were the result of beached floating ocean forests. The originators of the floating forest paradigm were biologists, arguing strongly from paleontological evidence that the dominant Paleozoic fern-tree plants were structured for a water environment. An in-depth and independent investigation would be needed to counter their conclusions, but such an investigation might serve to strengthen and extend their proposals if they were correct.

In this article the author reproduces some salient points brought up by the floating forest advocates while adding her own independent observational checks and calculations. Mathematical modeling of lycopods is initiated here by looking at their root systems. Some startling and significant finds have resulted from this analytical investigation.

What do Paleozoic fern-tree roots say about coal formation?

The first thing to note about the lycopod root system is that it is found fossilized in an amazing variety of distinct rock types.  Stigmaria are found in clay, claystone, shale, sandstone (including greywacke), limestone, and even coal.2 If Stigmaria were fossilizedin situ as the dominant paradigm assumes, then they were lithified in a wider range of ‘soils’ than any known plant can tolerate. Also, stigmarian rootlets were designed to be shed.3….

Continue Reading on