4.2" Cretaceous Tree Fern (Tempskya) Slab - Idaho
This is a beautiful, 4.2" petrified tree fern (Tempskya) slab from the Frontier Formation, of Caribou County, Idaho. It is polished to a mirror finish on one side to highlight the internal structure of the fern.
This comes out out of an old collection of petrified wood we recently purchased that includes a lot of pieces from unusual and/or no longer accessible locations. Keep an eye out for more rare pieces coming in the future.
Tempskya is a family of extinct tree ferns from the Late Cretaceous. They grew up to 15ft (4.5m) tall and is a small to medium tree fern. The trunk of Tempskya was what is known as a false trunk in that it is made up of a number of individual stems and petioles. This gives the petrified specimens a unique pattern.
Petrified wood is the name given to wood that has been turned into stone (fossilized) through the process of permineralization. All of the organic matter becomes replaced by minerals, while much of the original structure such as tree rings in retained. For this to happen the wood needs to be buried in an environment both low in oxygen (preventing decomposition) and with flowing, mineral-laden water. The coloration is due to the various minerals that are present during fossilization. For example red colors are due to iron compounds, greens due to copper, etc.