3-D Mazon Creek Horsetail Fossil Trunk Section

Description: The Mazon Creek deposits of the region near Braidwood, Illinois rival the other famous Lagerstatten of the Burgess Shale, Solnhofen, and Liaoning for the variety of detailed life preserved. Many exquisitely-preserved specimens are found in the ironstone nodules that make up the deposits. This fine specimen is a member of the genus Calamites , a member of the Calamitales which belong to the Sphenophytes. Whorls of small leaflets are arranged concentrically around a thin stem and are called Annularia (see my other offerings) or Asterophyllites. Calamites itself is the name originally given to a stem section, but now applies to the entire plant. These were indicative of humid to wet habitats such as along rivers and lake shores. This one is quite 3-D in preservation, and is what is called a pith cast, consisting of the longitudinal ribbed and grooved compressions of the plant. The only living example of the sphenophytes is the horsetail Equisetum.