With all the ferns and other spore-bearing plants around during the Pennsylvanian, you’d expect that there would be a lot of fossil spores, too. You’d be right. The science of palynology is the study of fossil spores and pollen. Because they’re microscopic, assemblages of spores and pollen make really good markers for particular time periods – often pretty short time periods, so they’re useful in biostratigraphy. They help explorers for oil and natural gas pin down pretty exactly where you are in the stratigraphic section, even when the information comes from tiny cuttings in wells.
The word palynology comes from a Greek word meaning “strewn,” or “sprinkle,” so it’s the study of things that are scattered or strewn.
|Pennsylvanian spore Reinschospora magnifica, about 70 microns across. |
From Kosanke, 1950, Illinois State Geol. Survey Bulletin 74.
The smallest pollen grains are around 6 micrometers across – it would take more than 100 to span a millimeter. Spores are similar in size, but they can range up to at least 90 micrometers across. Fossil spores come in a wild array of shapes, just as modern pollen and spores do. They’ve been studied scientifically since the 1800s but modern palynology really took off in the 1950s and 1960s. The American Association of Stratigraphic Palynologists was founded in 1967, and today under the name The Palynological Society the organization has around 500 members worldwide.
—Richard I. Gibson
Pennsylvanian spore Reinschospora magnifica, about 70 microns across. From Kosanke, 1950, Illinois State Geol. Survey Bulletin 74.