Seashell from SE Minnesota

[Acewas]

Hi everyone,

i am new to the forum,  I am from the east coast of the US but spend my summers in Southeastern Minnesota. I found this (what I think is an oyster shell or bigger Brachiopod) while agate hunting near Winona MN. But I have no idea, that is why I am posting. The Interesting thing about this fossil is that it is whitish with what looks like little worms or possibly sea weed? The shell is 2 inches long (50.8 MM) and 1 inch and 3/4 wide (44.45 MM). Please let me know if you need any other info to help identify what it is. 

[Auspex]

I am going to go out on a limb and suggest that this is a recrystallized and heavily water-worn rugose coral.

[caldigger]

Yeppers, looks like a rugose to me as well.

[Acewas]

2 hours ago, Auspex said:

I am going to go out on a limb and suggest that this is a recrystallized and heavily water-worn rugose coral.

HI @caldigger and @Auspex thanks for replying! I will check into rugosa coral. Any idea what the green lines are? 

[minnbuckeye]

I also have the worn rugosa feeling. But it looks so different than the horn corals that I find in SE Minnesota. If found in Winona, it probably was transported there by the river or mild glaciation or both since Winona is Cambrian.

 

 Nice Find! Where are the agate pictures????

 

 Mike

[caldigger]

4 hours ago, Acewas said:

HI @caldigger and @Auspex thanks for replying! I will check into rugosa coral. Any idea what the green lines are? 

If you are referring to the squiggly lines all over your piece, that might be from acidic root scaring similar to what is known as "lightening strikes" seen on teeth enamel.