Fossil specimen of permineralized or petrified wood from the Cretaceous of Seymour Island, Antarctica. Note the growth rings in transverse section. The knot is the site of a branch. Specimen is from the collections of the [Paleontological Research Institution](http://www.priweb.org), Ithaca, New York. Longest dimension of specimen is approximately 9 cm. Model by Emily Hauf.