~3cm "worm" imprint in agatized petrified wood? Found in central Oregon- Clarno Formation.

[Lexicon72]

I came across this piece while searching for petrified wood a little over a month ago.  I've been reaching out to various professionals and universities, and while folks have found the specimen fascinating, no one has been able to offer much of an explanation as to how this could have occurred since the soft-bodied creature would have had to leave an imprint that survived the many-year silification of the wood.  Bore holes are apparently common in wood, but nothing with this level of texture/detail.  Some have proposed the idea that the imprint was left in sap or a fine "paste" made from pulp, which then hardened and when through cell-replacement along with the surrounding wood.  Others have proposed it could be the result of the tree growing in around a bone fragment, etc... 

 

Very curious to hear from those who have seen this sort of thing before!

 

I'm also excited to be making my first post as a FF community member.   Rock- and fossil-hunting are a new hobby for me, and I'm loving it!

[DPS Ammonite]

Welcome to the Fossil Forum.

 

A closer more detailed photo of the texture of the imprint with help us to ID.

 

Here is my theory. The imprint sort of looks like a piece of wood with a web of cracks from drying out or having been burned. Note the series of parallel grain impressions that parallel the long direction of the imprint. When the main piece of wood was silicified, the space between the wood and the adjacent dead and cracked wood was filled with chalcedony and/ or opal creating an exterior mold of the cracked wood. What you see as raised ridges in the imprinted wood is the filling of the cracks in the dead wood. 

 

You have a great piece of wood. I especially like the green color.

[tmaier]

I agree this is not a "worm imprint", or imprint of any life form. It is a mineral growth inside of a void.

[fifbrindacier]

Nice find. 

[Lexicon72]

Thanks for the quick input!!  The theory that it was another piece of dried/burnt wood would certainly make sense, especially with the amount of volcanic activity in the area (literally in a valley surrounded by volcanic buttes).  My contact at the U of OR also speculated that it could have been from some kind of seed cone considering the consistency in the segmentation, though this wouldn't have really matched up with the time period of the Clarno Formation...

 

Here are a few more pics with a little more detail from several different angles.  This is just on my phone, so unfortunately I can't get too close and keep it in focus without the flash, which takes away some of the parallel line texturing in each cell/segment due to the glossy reflection.

 

The material itself is somewhat translucent, so pretty cool with a little backlight!

[DPS Ammonite]

Thanks for the clearer picture. I have to change my story a little since the "imprint" appears to stick out and have a positive relief. The lighting in the first photo made the feature look like it was an impression with negative relief. I think that feature is a piece of petrified wood or bark that has been fractured. Perhaps the wood burned or decayed before the rest of the wood. The chalcedony/ opal that silicified the wood appears to fill some of the cracks of the feature. Silica likes to fill all the cracks and voids in the wood during petrification.

[Lexicon72]

While the internal texture lines do stick out, the feature itself is definitely set into the piece of wood (~2.5-3mm at its deepest).  The edges are flush with the surface of the piece and are not raised.  Pictures are just never as good as the real thing!

[ynot]

Often when wood is petrified the outside of the piece will develop a "rind" of mineralization that is coarser than the interior. I think this is a remnant of the rind that was inside a crack/grove in the wood's surface. when the wood broke (after fossilizing) it left the bottom of the grove/crack"s rind. There are other pieces of the rind visible in the pictures. Notice also that it follows the grain exposed in the areas around it that have the rind removed.

Tony

[Al Dente]

One possibility is this was an insect burrow that filled with chewed up pulp and waste that later was mineralized along with the wood.

[Rockwood]

Modern hemlock.

[Shamalama]

3 hours ago, Al Dente said:

One possibility is this was an insect burrow that filled with chewed up pulp and waste that later was mineralized along with the wood.

 

I'm thinking something along those lines or perhaps a parasitic vine? It appears that the mineralized wood that surrounds the shape may have grown around an intruder? 

[JohnJ]

Is some of the same mineral making up the segmented inclusion also visible in other cracks...(it appears so in your last images)?

[ynot]

22 hours ago, ynot said:

Often when wood is petrified the outside of the piece will develop a "rind" of mineralization that is coarser than the interior. I think this is a remnant of the rind that was inside a crack/grove in the wood's surface. when the wood broke (after fossilizing) it left the bottom of the grove/crack"s rind. There are other pieces of the rind visible in the pictures. Notice also that it follows the grain exposed in the areas around it that have the rind removed.

Tony

Was tmaier the only one that read this?

 

Ynot

[Lexicon72]

11 hours ago, JohnJ said:

Is some of the same mineral making up the segmented inclusion also visible in other cracks...(it appears so in your last images)?

 

Some of the same coloration shows where there are tiny gaps/scarring, but most obviously within a few small tube-like features on one side (rightmost if you are looking at the initial pic in the thread).  It's hard to tell from the pics below, but they run through the piece from one end to the other.

[Lexicon72]

23 hours ago, ynot said:

Often when wood is petrified the outside of the piece will develop a "rind" of mineralization that is coarser than the interior. I think this is a remnant of the rind that was inside a crack/grove in the wood's surface. when the wood broke (after fossilizing) it left the bottom of the grove/crack"s rind. There are other pieces of the rind visible in the pictures. Notice also that it follows the grain exposed in the areas around it that have the rind removed.

Tony

Definitely a possibility since the wood from the area can often show distinct bark textures as a rind.  Here's a pic of a larger ~20lb piece I pulled out of the same spot (had to really dig for it!), with a clear bark rind.  I haven't seen anything in the area with the same structured segmentation as the specimen in question here, but that doesn't mean it's not there.

[Lexicon72]

18 hours ago, Al Dente said:

One possibility is this was an insect burrow that filled with chewed up pulp and waste that later was mineralized along with the wood.

Several others I've talked with in the paleontology community have proposed this as well...