Devonian wood fragments of an Archaeopteris progymnosperm. The wood part is also referred to as a Callixylon. These fragments were found in Bullitt County, Kentucky at road cuts.
This specimen was found in the New Albany shale. The Callixylon log maybe floated into this area from Pennsylvania or New York where it sank and was covered. The weight of layers building up over time flattened the wood pieces. Heat and pressure coalified or vitrinized the wood.