Brachiopod Id

[Allosaurus]

So I purchased this fossil a few days ago and I've done some research. At first i thought it was a neospirifer but upon closer examination I think it is actually a spirifer. I was told it came from florida and as my knowledge about Florida rock and fossils is rather lacking I was hoping I could get some other opinions

[Missourian]

It does look like Neospirifer (especially 1st pic), but the short wings make me think of Spirifer as well. It certainly did not come from Florida (unless there is some Pennsylvanian in the subsurface ).

[Allosaurus]

That's what I thought. I couldn't find a reference to neospirifer or spirifer being found in Florida, I keep thinking it's a spirifer because it seems to be slightly more round in the center than a neospirifer. I have an older invertebrates identification book and there are pictures of both next to each other.

Edited November 25, 2014 by Allosaurus

[Herb]

looks like a Devonian Paraspirifer bownockeri or more likely an Ordovician Platystrophia ponderosa.

Edited November 25, 2014 by Herb

[Missourian]

Plus, it has some Vermiforichnus-like borings (elongated pits).

[Missourian]

looks like a Devonian Paraspirifer browneki

Except for the middle part.

[izak_]

Spififer!

[erose]

Maybe a rock shop in Florida...

Ribs are too fine for Platystrophia and the Neospirifer versus Spirifer question may be impossible to answer without knowing the location from which it was originally collected.

[Allosaurus]

I asked the lady I bought it from and she said it came from the Peace River in Florida.

[tmaier]

Definitely not from the Peace River, unless somebody accidentally dropped it there. Not from Florida either. It is paleozoic, and Florida only goes back to eocene.

Paleozoic rock is more than 1/8 mile down below the surface, here in Florida. Some of those Peace River fossil fanatics get over zealous whilst digging, but holes that deep are not commonly found.

[erose]

Allosaurus,

Not unheard of for "odd" fossils to be purposely salted or accidentally dropped in the "wrong" location. It may have been found there, but for sure it isn't from there. Could easily see it being dumped when some collector from points north flipped his canoe.

PS that Invertebrate book you have is an excellent reference.

Edited November 26, 2014 by erose

[Allosaurus]

Paleozoic rock is more than 1/8 mile down below the surface, here in Florida. Some of those Peace River fossil fanatics get over zealous whilst digging, but holes that deep are not commonly found.

Well I don't know. Some people are pretty determined.

@Erose; thanks. I picked up the book on a whim at a rather old bookstore, not sure if I'd need it because I have another fossil ID book (which it turned out didn't include this mystery shell).

[Missourian]

I picked up the book on a whim at a rather old bookstore, not sure if I'd need it because I have another fossil ID book (which it turned out didn't include this mystery shell).

One can never have enough fossil ID books.

[tmaier]

The books can't show every species, but they are handy for a quick browse to narrow it down to a family or sometimes a genus. They just point you in the right direction. Then start scanning internet images under that family or genus name.

Neospirifer

http://www.google.com/images?q=Neospirifer&btnG=Search&hl=en&gbv=1

Spirifer

http://www.google.com/images?q=Spirifer&btnG=Search&hl=en&gbv=1

Paraspirifer

http://www.google.com/images?btnG=Search&hl=en&gbv=1&q=Paraspirifer&tbm=isch

Platystrophia

http://www.google.com/images?btnG=Search&hl=en&gbv=1&tbm=isch&q=Platystrophia

Or... you can drop back and punt, by doing an image search of the whole order of Spiriferida, hoping to stumble over the right family or genus...

http://www.google.com/images?q=spiriferida&btnG=Search&hl=en&gbv=1&nfpr=1&tbm=isch

Some of the unique features of your specimen are that it has fine ribbing, even on the fold,

the umbo gap between the two valves is fairly wide, i.e., at the hinge line the two valves have a large offset.

And the wide width of the hinge line, of course.

I don't find an exact match in anything... do you see anything?

(EDIT: I'm favoring the genus Neospirifer the most, due to the fine ribbing.)

Edited November 26, 2014 by tmaier

[Allosaurus]

Not sure if this is significant or not but I noticed one wing tip seems to point slightly up. The left side appears to slightly angle upward and the right slightly downward.

Otherwise the ribbing does tend to look like a neospirifer. The additional image I included seems to match fairly closely, but you'll note that there are horizontal ribbings along the shell whereas mine only has the vertical ribbing.

Edited November 26, 2014 by Allosaurus

[Missourian]

For reference, here are some Neospirifer (Upper Pennsylvanian-Missourian):

And some I have labeled as Spirifer (Middle Pennsylvanian-Desmoinesian):

[tmaier]

Not sure if this is significant or not but I noticed one wing tip seems to point slightly up. The left side appears to slightly angle upward and the right slightly downward.

That might be due to individual variation, or a distortion caused by pressure during fossilization. This is where is becomes hard to know what are population variations when you only have a sample of one piece.

The horizontal ribbing that you show are growth lines. The organism has a burst of growth, and that leaves a mark like a tree ring. I see them very faintly on yours, but they are extremely strong on the example to the right. Looking at Neospirifer images on the link above, prominent growth lines are not very common in those species of that genus.The strength of the growth lines can also be individual characteristics that are based on growing conditions. But on the other hand, very prominent growth lines or the lack of them can be a defining characteristic of a species population. Again, another case of the sample size of one not allowing the determination of what are individual characteristics from what are population characteristics.

Right now, I would say we are stuck at declaring "Neospirifer sp.", meaning we are sure it fits in the genus Neospirifer, but are unsure about the species. An extremely cautious person might back down the tree even further, and just declare this to be Spiriferida, which is a shotgun approach that declares all families and genus of that order. Professionals have to do things like that, because making a mistake has bad implications for them, but amateur collectors often plow forward and just choose the closed species, and call it a day.

If you want to do this the "professional" way, when you find the species it matches then you should walk through the written definition of that species and make sure that it meets ALL criteria of that definition. Normally the definition will also refer to closely related species, and you would want to chase all those definitions down also. Doing it "professionally" is a royal pain in the butt.

[Fossildude19]

Just to muddy the waters a bit more,... what about Mediospirifer or Spinocyrtia ??

Regards,

[tmaier]

Both of those genus have smooth or very subdued ribbing on their folds. The specimen in question has obvious ribbing on the fold, more like the species in Neospirifer.

[erose]

Not to beat on this too much but let's all keep in mind that since at this point in time the "location" is Peace River, Florida, and we all know that is certainly not the actual point of origin, then any identification at any level of specificity, or not, is TOTALLY speculative. Once again a great example of why solid location information is the most important item for a solid identification and scientific value. Allosaurus may have felt the seller was being honest, and maybe they were, in saying it was found in the Peace River. But there is virtually no way it can be from the bed rock or matrix of the Peace River and be that type of Spirifer. But this is always the risk with purchased fossils.

Now with that said, I would not at all feel uncomfortable labeling it as "Neospirifer? sp., location unknown". Using the quotes and question mark to indicate the tentative identification. It is a nice specimen and worthy of keeping as a good fossil. But it also has virtually no scientific value without accurate location info.

I have no idea how much you paid for it but hopefully not too much, whatever that would be. There are plenty of collectors who gather fossils because they just love fossils as interesting objects and the detailed science of each is not important. We collect for all sorts of reasons and could spend hours discussing what we each find important. But in the end we each find our own focus.

Where I have collected Neospirifers in Texas they are all too often crushed poor specimens. I would be quite happy to have that one with or without the location info just for it's own sake.

Edited November 26, 2014 by erose

[tmaier]

I would be quite happy to have that one with or without the location info just for it's own sake.

Yes, you should get rid of it immediately. Just send it to me.

[Allosaurus]

Yes, you should get rid of it immediately. Just send it to me.

Trust me, this one is going to stay in my collection.

I had my doubts on where the fossil came from, considering the person I bought it from didn't seem to know that much. I more or less picked it up as I thought it looked like a decent brachiopod (I paid very little for it) . The details for fossils that I purchase aren't as important to me considering I know that I have no way to verify anything of what I'm told. When I collect fossils however I do like to be specific (I find that I learn the most by uncovering my own fossils). But it's nice to be able to identify (or come close to identifying) what I have in any case.

I'll put it down as likely a Neospirifer. Thank you to everyone for their help!

[Fossildude19]

Both of those genus have smooth or very subdued ribbing on their folds. The specimen in question has obvious ribbing on the fold, more like the species in Neospirifer.

Ah,... thanks for pointing that out. I now know something I didn't, before.

Regards,