Southeastern WI Brachiopod ID

[SEWis-Fossils]

Here are two brachiopods that I hammered out of some rocks collected along Lake Michigan in Southeastern WI.  One of them popped out of the rock in perfect shape, the other was partially exposed and didn't fare as well.  These were from two different rocks.  They look similar, but I think that they are different species.  The pictures aren't great.  I had my kid take them since my phone camera is broken.

 

Let me know what you think.

[ynot]

@Tidgy's Dad, this looks like one for You.

[Innocentx]

Silurian/Devonian age brachiopods. Atrypa?

[Fossildude19]

Atrypa sp. or Pseudoatrypa sp. were my first impression.   

 

@Peat Burns  @Shamalama  @Jeffrey P

[SEWis-Fossils]

That's amazing how fast you came up with that ID.  It certainly looks like one of these two.  So, what's the distinguishing characteristics between these two(Atrypa sp. or Pseudoatrypa sp)?  A quick google image search shows that they look nearly identical.  I can get some measurements or take a few more pictures if that would help.

[Peat Burns]

4 hours ago, Fossildude19 said:

Atrypa sp. or Pseudoatrypa sp. were my first impression.   

 

@Peat Burns  @Shamalama  @Jeffrey P

That would be my guess, too.  Shamalama has provided a helpful comparison of general external differences here.  I'd lean towards Atrypa.

[Jeffrey P]

Atrypa is Lower Devonian and Pseudoatrypa is Middle Devonian. I'm not so sure about the ID. The first one looks like an internal mold. I'm not expert enough to determine a species by internal mold unless it is from an area I'm directly familiar with.

[Peat Burns]

Atrypa does occur commonly in the Middle Devonian, often contemporaneous with Pseudoatrypa.

[SEWis-Fossils]

Thanks guys!  I'm just looking for a close guess for my daughter who is in a fossil contest.

 

However, I have collected many a fossil in my time around this area, and might have to post the unidentified ones here.  You guys are great.  Thank you so much!

[Tidgy's Dad]

I think probable Atrypa too.

http://viewsofthemahantango.blogspot.com/2010/09/atrypa-vs-pseudoatrypa.html