Found in river bed

[Fred Toast]

Daughter found this in a stream bed today. 

First, is it actually a fossil, as we hope?

 

The scoring on the rock looks incredibly symmetrical.

The rock is quite hard, and I’m not sure what else could cause that kind of scoring, other than a fossilized impression of something.

Across the top of the entire rock: just under 5cm. (E.g., top photo)

Each ‘hash’ or ‘score’ is 5mm by 2mm.

 

Second, any ideas of what it is?

We’ve fossil hunted in the area and there’s a lot of Mississippian chert around there. Location circled in blue, if that helps.

 

thank you ahead of time; you all are so helpful!

 

Edited August 3, 2020 by Fred Toast

[Misha]

Looks like it could be an impression made by a crinoid columnal.

[Fred Toast]

Good one and thank you. 

We definitely have found the column segments here, but haven’t seen one here that would be that bulbous. The segments we’ve found have been in a tight, straight column, whereas if that did this, it would require more bulbous, Michelin Man like segments. :-)

Edited August 3, 2020 by Fred Toast
Adding thanks!

[Rockwood]

4 hours ago, Misha said:

Looks like it could be an impression made by a crinoid columnal.

Or 14 of them.  The bulbous look. Not a problem.

[Misha]

17 minutes ago, Rockwood said:

Or 14 of them.  The bulbous look. Not a problem.

Yes, I guess I should have said stem since a columnal is just one of the segments

[Mark Kmiecik]

The bulbous look may simply be a product of wear. Abrasion has the tendency to smooth things and round off edges and corners.

[Rockwood]

36 minutes ago, Mark Kmiecik said:

The bulbous look may simply be a product of wear. Abrasion has the tendency to smooth things and round off edges and corners.

It would have to occurred before the tendons that held the section together were lost. 

[Mark Kmiecik]

3 minutes ago, Rockwood said:

It would have to occurred before the tendons that held the section together were lost. 

I meant wear to the fossil imprint. This is an imprint, unless I'm mistaken, which of course is common for me.

[Rockwood]

5 hours ago, Mark Kmiecik said:

I meant wear to the fossil imprint. This is an imprint, unless I'm mistaken, which of course is common for me.

I just can't picture it happening that way. The wear is typically on high points. It would have to be oriented nearly perfectly level for setting water to cause cupping in the low areas in such an even manner. 

[Fred Toast]

Thanks! Super informative. (And my kids enjoyed the answers too)