I Realize How Unlikely It Is, But Could This Possibly Be Soft Tissue Remains On This Little Disarticulated Fish Fossil?

[claire01]

Cenomanian, Eagle Ford. 3" x 2.5" approx.

Edited September 17, 2014 by claire01

[Xiphactinus]

Looks like mineral deposit to me. Maybe bentonite. We find layers of red bentonite in the Niobrara Chalk of Kansas that looks a lot like that.

[fossilcrazy]

Hi claire01,

A quick answer to your question is No, it is not. When we talk about fossilization, soft tissue remains would be like Woolly Monmouth hair found in ice or like skin or chitinous remains of a species. Now there are occasions that soft tissue preservation is found when mineralization replaces organs of a species; for example fish in the Santana formation of Brazil, the Myomere or muscle tissues along with bones and scales are preserved. I cannot say if your piece in question is soft body preservation.

Hope I made the distinction understandable.

[claire01]

Thanks very much, both of you. I've found these little fish before, but never with that red on them.

[Ramo]

Claire01, It most likely isn't soft tissue preservation, but I wouldn't rule out that the fish remains didn't contribute to the reddish mineral deposit. I find similar fossils in the Lincoln Limestone here in Kansas, and I also find what I would consider unusual mineral deposits around bone. I'm not sure if the bone "attracts" minerals to the area, or how it works, but concretions are often found around something fossilized. Right now I'm working on some large vertebrae in a rock not too different that what you have there, and there is a red line around a lot of the bones. It is not right next to the bone, but it is definitely associated with the bones.

If that red "stuff" isn't usually found on the rocks in that area, then that almost has to be associated with the fish vertebrae.

Ramo

PS, I have used an air scribe, and boiling vinegar to prep out similar stuff. Thought you might want to try one or the other, or both if possible.

Edited September 18, 2014 by Ramo

[claire01]

Thanks, Ramo. It was unusual looking. I picked it up based solely on what I saw in that first image as the back was completely obscured by that white coating that covers most of the rocks in that spot. You can still see a little of the remains of it around the edges. It wasn't until later, after I had a chance to clean it up, that I saw those little bones and realized it was a fish.

I haven't tried boiling anything in vinegar before but am looking forward to trying that out, thank you! And I did get my engraver back out. I had put it away after ruining a little crab claw but trying to clean things up by hand is becoming tedious. I hope to someday have an air scribe.

[Auspex]

In anoxic conditions, bacterial activity (read "poop") can precipitate iron in various forms (depending on what's available).

The soft-tissue preserved in the Messel Shale is of this type.