The Proceedings of the Eighth International Conference on Creationism (2018)

eroded plant detritus was transported in rivers as dispersed grains and settled through water in lakes, submerged parts of deltas or marine estuaries. Both early and later allochthonists of the French School used the “petrology-strata-paleobotany-environment” methodology to understand the origin of Carboniferous coal. The floating mat model has a robust three-hundred-year history that was summarized for the first time by Austin and Sanders (2018). About the same time as the French School of allochthonists was developing subaqueous notions for coal deposition and elaborating the drift model, another group of allochthonists already had an alternate understanding. This second group of allochthonists was uneasy about coal plants being grown on upland terrain and then transported as debris by rivers to lakes or deltas. This group proposed coal-forming plants existed on large floating rafts of vegetation and that coal was deposited as vegetation sank, either en masse or as broken detritus. Assigning only secondary importance to the paleobotany, these early allochthonists understood Stigmaria to be a solitary, prone-floating rhizomorph with water leaves, that when tangled with floating debris, became able to sprout an upright lycopod trunk. Three prominent early advocates are German botanist Otto Kuntze (1884, 1895), the British-American engineer and geologist William Gresley (1894a,b), and the Cambridge University paleobotanist Albert Seward (1895a,b). Later advocates are petrologist Steven Austin (1979, 1991), paleontologist Joachim Scheven (1981, 1996) and paleontologist Kurt Wise (2003). Paleobotanical observations favoring the floating mat model appear in the following pages. Austin and Sanders (2018) observed that historically the drift model and the floating mat model of allochthonists used the “petrology-strata- paleobotany-environment” methodology to understand the origin of Carboniferous coal. What about those lycopod “roots” in strata above and below coal beds? Is the iconic coal fossil Stigmaria really indisputable evidence for growth in place of roots in fossil terrestrial soils? Robert Gastaldo (1999) defends autochthony calling it “Empirical science versus the diluvialists.” How strong is the evidence from upright fossil trees grown on elevated terrestrial surfaces? Even creationists Tim Clarey and Jeff Tomkins (Clarey 2015, Clarey and Tomkins 2016) are persuaded that lycopod trees within Carboniferous strata in Glasgow, Scotland grew as a forest on terrestrial soils. Are the evidences straightforward observation? Examples of Carboniferous forests supposed to have grown in place have appeared in the literature (surveyed in DiMichele and Falcon-Lang 2011, Thomas and Seyfullah 2015). Could those “forests” instead be floated and grounded mats of vegetation? All these questions show us that there is a critical need to revisit lycopod and tree fern anatomy. Paleobotany needs to be considered in detail, and attention needs to be directed at alternate depositional models. That will focus our clear thinking to make progress in understanding the origin of coal. Therefore, given the pervasive acceptance of the autochthonous origin of Carboniferous coal in coastal mires or swamps among conventional scientists, and given the objections to the floating forest biome within the creationist community (Clarey and Tomkins 2016), we examine here the biology of the dominant coal plants in the post-1940 conventional paleobotanical literature to provide sound support by the scientific literature for a floating lifestyle. Detailed documentation and extensive, in-context quotes are provided for lycopsids in Appendix A and for the tree fern Psaronius in Appendix B. ARBORESCENT LYCOPSIDS The basic structure of arborescent (tree and treelike) lycopsids has been widely discussed and illustrated in the creationist literature, especially Scheven’s (1996) Figures 1, 3, and 8, which have been reprinted by various authors. Therefore, a basic description of these plants is unnecessary. The interconnections of the fragmentary fossils of these plants are well enough known now for the organs of each biological species to go under a single name instead of separate form-genera and species. One exception is that the rootlike horizontal axes of most species are identical and cannot easily be assigned to a particular trunk genus and species. These are assigned to the form genus Stigmaria , and usually to the form- species S. ficoides . Hence these organs are often referred to as stigmarian axes or systems, though recent paleobotanists usually use the term rhizomorphs or rhizomorph axes. The structures radiating from these axes are usually called stigmarian/rhizomorph rootlets or appendages, depending on how the author is interpreting their homologies. The overall anatomy of the rhizomorph axis and appendages is shown in Figure 1. The arguments that we make below are better understood using certain technical terms. Concerning stem and rhizomorph anatomy when these growing organs first matured, they consisted only of tissues generated by the apical meristems and, thus, were considered to be all primary tissues. At this stage, the primary tissue between the stele (the thin central core of primary xylem) and the outside of the organ is termed the cortex, which consisted of three zones. The inner cortex was a thin layer of fairly delicate parenchyma cells surrounding the stele. The middle cortex was a fairly wide cylinder, of which the composition has been debated as discussed below. The outer cortex consisted of fairly tough parenchyma cells that provided initial external support for the organ. Secondary tissues, giving extra support, were formed when certain cells of the primary tissues began to divide and generated radially aligned rows of cells. Thus, secondary xylem produced by and surrounding the stele made up most of the internal wood cylinder. (Because of the limited amount of secondary xylem and its similarity to primary xylem in these plants, paleobotanists often include the secondary xylem when speaking of the lycopsid stele, which we will follow in this paper.) Periderm was secondary cortex arising and growing in the mid-regions of the outer cortex and became much thicker and more supportive than the outer cortex. The colloquial term “bark” is usually applied to the periderm (secondary cortex) and cells of the outer cortex (primary tissue) that closely adhered to the periderm. Concerning the diversity of arborescent lycopsids, there are six major genera. The plants of three ( Lepidodendron , Lepidophloios , and Synchysidendron ) were quite tall and distinguished by the trunks being unbranched except at the top, where the apical meristem was dissipated by successive dichotomous branching. These differed primarily in the degree by which the sporophyll base flanked and enclosed the megasporangium, which contained a single permanently encased megaspore (thus, monosporic). Sanders and Austin ◀ Paleobotany supports the floating mat model ▶ 2018 ICC 526