Permian Petrified Wood

[Rick_Jo]

Hi All,

I have been collecting a bit of petrified wood of late and wanted to put a name to the Permian plant from which it came.

The photo below is the most common type of wood that I have found, however I have found various kinds that I would be happy to post should anyone be interested at having a go at ID-ing..

This sample is from the upper Permian formations of the Sydney Basin Australia, manly comprised of siltstone, mud stones and sandstones deposited (in this particular area) from a fluvial deltaic setting. As there is various coal layers throughout the formations, from cool climate peat deposits I would say that it would be something along the lines of Glossopteris or some kind of seed fern? (I have found Glossopteris leaf fossils in near by formations).

If anyone is good at ID-ing wood, suggestions would be much appreciated

[Paleoworld-101]

Based solely on Glossopteris' sheer abundance and dominance in Gondwana during the Permian period I would say that is what it is most likely to be from.

Cool find!

[paleoflor]

Very nice find. Dadoxylon is a very broadly defined form genus that is sometimes associated with Glossopteris (then again, also with a great many other plants, like Cordaites). Nevertheless, it might be worth looking into this form genus. Note though, that the sheer abundance of Glossopteris leaves is generally believed to be (at least partly) due to seasonal shedding, i.e. Glossopterids are thought to have been deciduous plants. To me, the "ID" as Glossopterid is by no means certain, or even any more likely than other plant types, such as conifers (your locality is ex situ, as the logs have undergone fluvial transport, so both low- and highlands can be considered). Furthermore, for reliable identification of petrified woods you will need thin sections. To see why, take for example this paper by R.A. Savidge (2007) dealing with the syntypes of Araucarioxylon arizonicum. The types were found to be anatomically distinct in thin section, leaving the form genus Araucarioxylon illegitimate.

[RomanK]

Nice find! Congrats!

[Rick_Jo]

I have been meaning to join the lapidary club to polish some of them up. I will repost once I have some better polished samples as I can see that from the picture vestigial structures are hard to distinguish.

What is interesting about a majority of the wood similar to this that I have found is that the growth rings are not circular, most being from an apparent 'gnarly' kind of plant, does this help at all?

Thanks for the replies!

[paleoflor]

Polishing will help a great deal. So far, only thing I could tell is that the growth ring boundaries are distinct and the rays are not (so the latter are probably thin or absent). Meanwhile, have a look at this website. I do not know whether it will work magic for Permian woods, but it is an informative site anyway.

[izak_]

Nice find! Probably glossopteris or another seed fern of some sort? Imagine how big it would have been!