reptile skin

[Shalon]

I have some questions please if someone would be so kind as to answer, it would be appreciated. I am including a photo for illustration purposes only. My camera is broken and I took this with my phone for easy uploading. I am not asking for authenticity ratings based on phone pics. Early spring garden find that was set aside as a curiosity then, forgotten. While researching other things, I came across some references to " dinosaur skin" fossils. I pulle d this out of the box and looked again. This piece is close to 2 in. on each side and 3/8 thick but one plane curves at the middle creating one point of the triangle that is 1/4 thick. The pattern is the same on all of the other sides of it also. Although 2 of the edges are much smaller " grain" and and very lightly incised. The piece was wet for this picture so that the detail would stand out. So, my questions are, how rare is it to find fossil reptile skin? Has anyone here ever found or seen anything like it? It is the same color and texture of some museum fossils but at first uneducated glance last spring, I had thought it might be iron. Have you seen artifacts made with fossils? How about fossil bone and teeth worked as though it were stone? What other things could this be?

[painshill]

In general, soft tissue (and that includes skin) rarely fossilises well such that it survives in a form that is still recognisable. As for dinosaur skin, well there have been occasional finds in exceptional circumstances of preservation, but they are extremely rare.
The fossilized remains of a Hadrosaur were found in the Hell Creek formation in 1999, which included not just bones, but fossilized soft tissues like skin, tendons and ligaments. It was the first-ever find of a dinosaur where the skin "envelope" had not collapsed onto the skeleton. It appears the animal mummified in hot, dry conditions before it was buried and fossilised… that’s what preserved the skin detail.
Skin impressions (ie the negative cast of the skin in clay that has become rock) are a little less rare. Fossilised scutes (the tough bony plates that sit on top of the skin in animals like crocodiles) are very common finds if you’re in the right area.
Even among the limited number of claimed skin fossils and impressions, a substantial proportion of them are disputed because there are many other things that can resemble skin… like the fossilised Bryozoan mats that Pam has been posting and also inorganic sedimentary structures with shrinkage cracks which have metamorphosed.
Even without clear pics, the clues to your piece not being skin are the size variation of the “scale” pattern and the fact that the pattern is the same on all sides. Skin would have the pattern on one side only (the exterior). The fact that it is thin and flat suggests that it’s more likely to be a fossil than a mineral nodule but it’s difficult to say either way unless it is high in iron… and then it’s definitely a nodule that has come out of sandstone. Bryozoan or sponge fossil would be the other possibles. Better pics might help, but it looks fairly water-worn to the extent it would have lost any useful identifying features.
There’s absolutely no reason why artefacts cannot be made from fossils if the material has mineralised in a suitable manner, although I see no artefact-like features at all in your piece. Fossil wood is a moderately frequently encountered material for points – especially fossil palm wood.
Roger

[Shalon]

Even after a year of learning, I still can't find an explanation for this piece. The longest dimension on it is about 2", the pattern does get very small and fine on the sides and in some other places and in one place, right where an eye should be, if you are a fanciful type, there is an opening in the pattern. It is still quite the enigma.

[painshill]

Let's see the other side and one of the edges... a little sharper focus if you can.
Fossil (but not skin) remains a possibility, but this is "lizard-skin" sandstone (not fossil) and it could also be something in that territory:

[pic from Desertrose's blog site on wordpress.com]

[Shalon]

Ok, better pics. It's just a silly little thing but it just makes me think "huh", everything I look at it. Also, I've included a pic of each plane and all 3 edges. And oh my. The color is horrible. It is actually a nice brown with a couple of darker brown places.

[painshill]

Hi Shalon
Thanks for the better pics. That helps a lot. It’s now clear that we’re looking at something composed of a cluster of small 3-dimensional irregular polyhedra. Those patterns are not just on the surface, they run through the rock like a network and they are definitely not organic structures. They’re shrinkage cracks.
Normally when you see those, they have a purely mineral origin and they arise in round or oval forms known as “septarian” concretions. The cracks are usually much bigger and frequently fill with a secondary mineral such as quartz or calcite that provides a contrasting colour.
That’s not the case here and that leads me to conclude that we’re looking at a clump of something that was a solid organic mass with a high water content (most likely plant origin) which has shrunk to create the cracks while it was drying out and being mineralized. There are several possibilities, but I would suggest that it’s probably a chunk of mineralised (ie fossilized) partly-decomposed wood that had been in water or mud for a long time.
Here’s a chunk of carboniferous limestone derived from partly-rotted wood exhibiting the kind of effect I’m describing:

Here’s a polished cross section through a chunk of chert derived from silicified peat (partly decayed vegetation – typically moss) which shows a similar effect:

[Both pictures from Hans-J. Weiss’s “Chert News” website]

[Jeffery Howle]

I don't know what it is but its neat...ya I said neat(shows my age)...But I would trust painshill  opinion on this he knows what he's talking about....thanks for sharing

[Shalon]

That makes sense. Thank you very much for taking the time to look and reply with such great information.