Unknown Fossil Bone ID

[MacHoffman22]

I found this specimen where I have found most of my others, near a cow pond off of Vermillion Lake about 16 miles from Sioux Falls. I am very curious as to what it might be true to it's smooth and refined shape.

[Shellseeker]

I think it is a proximal phalanx...

You can see what a few look like here... size is a likely differentiator.

 

[Plantguy]

I can see the phalanx resemblance that Shellseeker suggested but on my desktop now with a larger computer screen I think I can now see internal parallel fine lines which makes believe it might actually be a worn belemnite fragment with the interior groove possibly being the phragmacone....

Here's a closeup of a internal view of a piece I have showing the internal growth layers and a worn phragmacone--triangular shape on the right ( ...entire specimen is about 3cm long. 

Here's a photo of a more complete specimen of Pachyteuthis from South Dakota. Not sure that's the genus for yours--someone else may be able to say more or say no. They were kind of stocky/chunky compared to other pencil bullet shapes and kind of elliptical in cross section as I recall with a shallow furrow along the base. 

Regards, Chris 

[Shellseeker]

8 hours ago, Plantguy said:

I can see the phalanx resemblance that Shellseeker suggested but on my desktop now with a larger computer screen I think I can now see internal parallel fine lines which makes believe it might actually be a worn belemnite fragment with the interior groove possibly being the phragmacone....

Here's a closeup of a internal view of a piece I have showing the internal growth layers and a worn phragmacone--triangular shape on the right ( ...entire specimen is about 3cm long. 

You have better , younger eyes that I do , Chris.  I like your identification much better than mine. Jack

[Plantguy]

5 hours ago, Shellseeker said:

You have better , younger eyes that I do , Chris.  I like your identification much better than mine. Jack

@Shellseeker I dont know Jack about the better eyes as between the bifocal wearing and the retina guy I saw last week saying I was a surgery candidate just waiting to happen--it might be a tie with you on the eyechart reading. As it turns out I got the 1st photo up side down and the triangular phramacone opening is not on the right of my specimen but actually the left on my photo. LOL.  Oh well I tried! 

 

Regards, Chris