Brachiopod? If so, what species?

[sisterlama1243]

Hello,

I am new to the fossil world and I am attempting to identify this fossil which is most likely from the Lower Mississippi River Valley in Illinois. I believe it is a brachiopod though am a little confused as to the difference between brachiopods and bivalves. Is there a way to determine the specific species of brachiopod? Also, if you know any additional information I would love to learn more about this fossil!

Edited July 27, 2016 by sisterlama1243

[Fossildude19]

Welcome to the Forum.

It is indeed a brachiopod, possibly some sort of Spiriferid.

This pic from a website explains the difference between Brachiopods and Pelecypods.

Hope that helps.
Regards,

[sisterlama1243]

VERY helpful! Thank you!

-Jenny

[Pumpkinhead]

Looks like a brachiopod to me.

There's a few differences between brachiopods and bivalves. The easiest way to tell the difference between them is their symmetry. As you can see from the image below, brachipods have their line of symmetry drawn from the top to the bottom valve, while things like clams have their line of symmetry drawn between their right and left valves. The top and bottom of a clam will be virtually identical, while in the case of brachiopods its the right and left.

Brachiopods and bivalves belong to different phylums. Brachiopods belong to phylum brachiopoda, while bivalves are mollusks.

Brachiopods are also lophophorates, as they have a lophophore which is essentially a bunch of coiled ciliated tenticles which they use to feed. Bivalves have different methods of feeding.

[Fossildude19]

Jenny,

Have a look at these links.

LINK 1 - from looking at this, your braciopod may be a Punctospirifer. (maybe someone more local/knowledgeable than I can chime in and help with the ID's).

LINK 2

and

GEOLOGIC MAP of Illinois

Usually, you try to figure out where it was found, ... the age of the outcrops in that area/county, then look for resources describing the fossils from that time period in that area.

Regards,

[Monica]

Hi Jenny!

Welcome to TFF!

I'm also new to fossil-hunting, but I agree with what Fossildude19 and Pumpkinhead have said - it looks as though you have found a brachiopod. To me it looks as though the brachial valve is what is visible on top and the pedicle valve is underneath - the pedicle valve has the pedicle opening (if there is one - sometimes it's absent) and this valve has a "beak" that extends beyond the hinge line between the two valves. Bivalves don't have this asymmetry.

Thanks for sharing your find!

Monica

[CraigHyatt]

That is such good stuff about the brachiopods. Thanks!

[Monica]

That is such good stuff about the brachiopods. Thanks!

Hi Craig!

When I was trying (unsuccessfully, unfortunately) to identify the brachiopod I found in the arctic, I did a little research into brachiopod external morphology - I'm glad that it has come in handy to help out some others on TFF :-)

Monica