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Our view of the past is built from countless stony fragments and impressions left in sedimentary rocks by fortunate, yet improbable accidents of preservation of once-living tissue. The history of the group of plants that we know as cycads is a long one; yet, they have left us only a few scattered clues to the richness of their reign. The fossil species discovered to date are named for leaves and leaf fragments, for cones, and for stems. Only rarely, as in fossil animals, does a generic name refer to the intact plant. The vegetative fossils we find in ancient sediments are mostly the storm debris of prehistoric forests, a stump, or sodden log, or a pile of leafy debris gathered in an eddy and buried for future detectives to decipher. The names of some of those "detectives" remain prominent even today: researchers like Seward, Wieland, Williamson, and Chamberlain. Wieland's American Fossil Cycads, volumes 1 and 2, is one of the classic reference works in this area. And Chamberlain, whose The Living Cycads is another classic, also wrote in-depth on cycad evolution in his Gymnosperms, Structure and Evolution. It is through the dogged physical labor of field paleontologists, the technician in the lab who frees the fossil for study, and the determination and insight of researchers who try to bring together the pieces, that we have any knowledge at all of these vanished worlds. It has just been in the last century that an explosion of knowledge has occurred as the science of paleontology has matured. |
Like a grimy window being wiped clean, our view of the past grows better and better with each passing day. This article is a brief review of current knowledge of the fossil cycads. Photos and drawings of representative fossils are included. As you can see we don't have a lot of clues to go on. But with each new dig, the fossil record is enhanced with additional pieces of evidence. |
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