South Dakota fossils

[Dakota Banjo]

Hello--I have no experience hunting or identifying fossils; these four pieces came off the same hill near Lake Sharpe (Missouri River, central South Dakota). I guess glaciers were not supposed to have come through this area--it is much more rugged than east of the River. I am no expert but it is pretty clear all four are fossils, I would think bone of some sort. They are rock hard (and heavy), and one in particular shows quartz or some sort of crystal in the cross section on the end that appears to be a break (not seen in the photo below). I think they actually represent three pieces--the two thinner ones (below the ruler) were found a couple inches from one another and seem to nest on top of each other, in which case the stack of the two thinner is analogous to the other two thicker fossils. A picture is doubtless better than words!

 

All the fossils are partially encased in dark sedimentary rock, seen best in the top right. It honestly looks like dry mud, but it has

the hardness and density of rock. I have some other photos, but the one seemed to be the size limit for uploading. Any help in

identification is much appreciated; let me know if you have any other questions! Thanks.

 

 

[Dakota Banjo]

(The two thinner fragments)

[Dakota Banjo]

Here is the underside of the two thinner fragments.

[Dakota Banjo]

The apparent break on one of the thicker fossils--here you can see the channels of quartz or mineral; towards the top

and right the rough grain of the fossil is seen (it almost looks like wood, were it not for the shape of the top face, and 

some cancellous bone on a couple ends of the fossils).

[Ludwigia]

On the one hand, you state that you have no experience, but on the other hand you say that it is clear to you that all four pieces are fossils, and you think bone. What leads you to this conclusion?  I'm sorry to say that I don't recognize any bone substance in your photos, but perhaps more highly resolved pictures showing the fine details would help better with determination.

[Dan 1000]

I am going to second Ludwigia and say not a fossil. I am not seeing bone.

[Rockwood]

Sounds like we're looking at Cretaceous material. I can picture it being part of a large plant, but since I've never seen the exact features I can't be certain.

[RJB]

Looks like wood?

 

RB

[minnbuckeye]

Last pic vaguely resembles mammoth tooth?????????

[Miocene_Mason]

I’m in the lignite (wood fossil) camp. 

[GeschWhat]

Dark sedimentary rock and location suggest this was found in the Pierre Shale, which would make it a marine environment. Something fishy perhaps?