This picture is of coniferous tree twig that has turned to coal.  It was found in Austria. The fossil dates to the Oligocene Epoch of th...

This picture is of a fossil tree stem preserved in silica. This mineral preserved the air pores or lenticels. It was on display at the ...

This picture is of a palm stem silica fossil. It was found in Sardinia. The fossil dates to the Tertiary Period. It was on display at ...