Can Enyone Id Small Marine Tracks?

[Salvageon]

My son found these tracks amid marine fossils in an inland sea. They are very small, round and in long trails. Thank you

[Auspex]

Were they in the Roundup, Montana area? Can you give us an idea as to their scale?

[Salvageon]

The fossil is only 6" high by 5" wide and found about 40 miles North of Roundup near Winnett by a lake. There are a lot of snail clusters and worm tunnels in the mud stone along the shore.

[Auspex]

Thanks, I had imagined it to be much bigger...

The trackway looks more like something either undulating or bumping along the bottom (as opposed to walking or crawling). Nothing specific comes to my mind, but someone here may have at least some ideas; stay tuned!

[PFOOLEY]

It looks like they may be remnants of Ophiomorpha burrows. I see them here in Cretaceous sand stones.

There has been some discussion on the Forum about similar specimens...see here and here for examples.

Edited March 13, 2015 by PFOOLEY

[Tethys]

I too see some sort of seastar or brittlestar. I think I can see more arms within the matrix on the right side and at the bottom of the central orange body section, but the photo doesn't show those areas clearly.

[Salvageon]

There are lots of mud burrows all over so the shrimp are a good bet. I googled up pics of ghost shrimp fossils and they showed large areas of burrows like we have. I thought the burrows were from worms. Next trip I'll take a picture of them and post it. Thanks