Iowa Mystery Bone ID

[MacHoffman22]

Need help identifying what appears to be a tooth or bone of some sort. Found in the far northeastern part of Iowa (almost South Dakota) about 8 inches deep in the sandy shore of the Big Sioux River. The left and right side appear to be very slightly broken off, as well as what I would assume to be the bottom.

[Mike from North Queensland]

Looks turtle to me but wait for the locals to confirm as I could be way off

[fossilus]

Look alot like a piece of turtle shell.

Depth of burial doesn't mean much generally in a sand point bar in a river as they can be deposited very quickly.

[caldigger]

Mike has it on the money.  It is turtle carapace shell.

[MacHoffman22]

Much appreciated. I'm not sure why turtle never crossed my mind.