Sigillaria Fossil

This cast fossil of the trunk of a Sigillaria, an extinct giant scaled tree that stood well over 100 feet tall when alive is the latest addition to the Everhart Museum landscape. Dating from between 299 million and 323 million years ago, a geological period called the Pennsylvanian period, a subpart of the Carboniferous period, it was formed when the space left behind by the decayed Sigillaria was filled with minerals and sediment over millions of years.

Occurring well before the first dinosaurs existed, the Pennsylvanian period is associated with receding seas producing tropical swamps with an abundance of plant life, including a group of Lycopods, or club mosses, referred to as “giant scaled trees.” Despite their name, the so-called giant scaled trees were not truly trees as they were soft and lacked real wood. Two giant scaled trees dominated the landscape: Sigillaria, which had ribs and round leaf bases as evident in this specimen, and Lepidodendron, which had diamond-shaped leaf bases.

The swamps of the Pennsylvanian that yielded such plants would alternatingly be covered and uncovered by shallow seas as periods of glaciation in the Antarctic region locked up and then released water over hundreds of thousands, if not millions of years. When Sigillaria died, its trunk, leaves, and root systems became buried by oxygen-depleted water and sediment, which protected the plant material from decay and allowed for fossilization.

Sigillaria fossils are important evidence of the ancient forests that formed the coal deposits we have today. This specimen was excavated during the construction of the Casey Highway, a few miles east of Scranton, and weighs 2,700 and 3,000 pounds.

We would like to take this opportunity to recognize the Weidlich Family for this gift in memory of James F. and Patricia A. Weidlich.

We also thank R. Stephen Carter for providing information on this specimen and assisting throughout the process, as well as Jeff Wallis, Randy Wallis, Paul Summa, Jack Figured, and Paul Spott for constructing this display.