Florida palm "wood"

The common practice for petrified wood is to use "form genera" names for specimens, thus all petrified palm fiber is described as Palmoxylon sp and the roots as Rhizopalmoxylon sp. The reason for this convention is that the wood rarely gets as much attention as the foliage when plants are described and these components are rarely, if ever, found attached.

In the Early Pleistocene, about two million years ago, this bit of trunk was driftwood in the paleo Santa Fe River. The waterlogged wood sank to the bottom in a basin in the river channel. They became buried in a highly organic mud during seasonal flooding.

This anaerobic, low-energy burial preserved fine details such as bark and even insect borings. The wood is thoroughly mineralized with apatite (not "silicified" as labelled) -- it 'clanks' when two pieces are tapped together. 

This wood is dated biochronologically by the vertebrate fossils also found in the mud, notably Holmesina floridana, a giant armadillo. Fossils of the beavers Castor and Castoroides, muskrats, grebes, cormorants, ducks, and large fish suggest that this was a backwater pool in the river.