Animation of fossil foliage (part and counterpart) of the fern *Crenulopteris acadica* from the Pennsylvanian of Kanakee County, Illinois (PRI 42681). Pinna (portion of a compound leaf). Marattioid fern (Order Marattiales, Family Psaroniaceae). Specimen is on display at the [Museum of the Earth](http://www.priweb.org), Ithaca, New York. Length of specimen is approximately 16.5 cm. Model by Emily Hauf.