Devonian Goniatite. ID requested

[Ludwigia]

3 hours ago, Al Dente said:

If this were my fossil I would send some photos to a Paleozoic ammonoid expert to get his or her opinion. To me the sutures look too complex to be Devonian but the preservation looks the same as the goniatites found there.

 

These are exacly my thoughts. Can you suggest someone I could contact?

 

 

1 hour ago, FossilDAWG said:

I've gone through a couple dozen papers on Middle Devonian ammonoids looking for anything with an ammonitic suture, and come up empty.  Everything I have seen is a goniatite.  Is there any chance that this tiny specimen is actually from some Mesozoic European site and got stuck in a fold of a collecting bag?

 

Don

 

1 hour ago, Kane said:

Hm. I do recall a good European collecting there recently.  

 

Thanks for looking into this, Don. Unless by some freak chance I can locate a second specimen, perhaps Ockham's Razor is the conditional answer at this point. I'll still keep the candle of hope lit in the very remote chance that this is a precocious newcomer to the Devonian  

 

50 minutes ago, middevonian said:

Aside from the obvious issues with morphology, preservation seems off for either the Arkona or Widder Formation. When also taking into consideration the uncertainty of who collected the specimen, at what locality and how it was collected I think it would be difficult to make a strong case for it being from the area.

 

I've been checking out lots of papers, etc. as well with the same results. I'm thinking more and more that it could have been dropped there, but one thing's for certain. It's not from me. Even if it was inadvertent and completely unconscious, I have never collected something like this in my life.

 

 

[doushantuo]

minor threadjacking:

tfwwwopac.pdf

outtake:see below

Roger,I noticed Pal. Polonica 63 by Dzik has a large section on goniatites,with pretty good figures .

Just saying

 

[doushantuo]

widder

[Kane]

Hm. It's not as collected a site as it once was. And given that it isn't coming from you, this is a big wrinkle. As I said, a second find might be necessary, even if that does not guarantee confirmation that it is native to the site. It's certainly not coming from the tread of my boots since I haven't stepped foot on Mesozoic soil in eons! Roger, are you absolutely certain this didn't get mixed up with anything on your end (matrix debris)? I don't suspect that it is, but just to rule it out. 

 

And, @doushantuo - No threadjacking! And it is not the Widder (Wright's analysis is now a bit dated), but found in the Arkona. Contiguous, but very different. This is now a "forensic scene"  We need to see if we can get to the bottom of this. In Sherlock Holmes' terms, this may indeed be a "three pipe problem"! 

[doushantuo]

BTW:Arkonips (Hungry Hollow, Middevonian,Ontario)is preserved pyritically.

I know that about the Wright piece,Kane,

And you know i know.

Post in haste ,repent at leisure

I tend to to let my mistakes stand,as they might be educational,or even point towards amusing European intellectual backwardness

The archivically minded might enjoy that piece,anyway.

 

 

[Guest11596]

36 minutes ago, doushantuo said:

BTW:Arkonips (Hungry Hollow Middevonian,Ontario)is preserved pyritically.

I know that about the Wright piece,Kane,

And you know i know.

Post in haste ,repent at leisure

I tend to to let my mistakes stand,as they might be educational,or even point towards amusing European intellectual backwardness

The archivically minded might enjoy that piece,anyway.

 

 

Pyrite preservation is not the issue. The specimen seems to be partly covered in, what appears to be, limonite. I've only seen that happen in two horizons. On of those horizons doesn't occur at Hungry Hollow and to the best of my knowledge the other has no occurrences of ammonoids.

[Kane]

1 minute ago, middevonian said:

Pyrite preservation is not the issue. The specimen seems to be partly covered in, what appears to be, limonite. I've only seen that happen in two horizons. On of those horizons doesn't occur at Hungry Hollow and to the best of my knowledge the other has no occurrences of ammonoids.

I think we've narrowed it down to Arkona Fm. Are there limonite traces there? Of course, without specimen in hand, I can't say for certain if it is set in some limonite. But you are probably pointing to the right tree to sniff up: the matrix in the centre of the whorl. That might be the key.

[westcoast]

Loving this topic but not seeing the limonite that @middledevonian is seeing...looks like pyrite to me. Logic be damned I'm really hoping those sutures are Devonian. 

[Kane]

10 minutes ago, westcoast said:

Loving this topic but not seeing the limonite that @middledevonian is seeing...looks like pyrite to me. Logic be damned I'm really hoping those sutures are Devonian. 

Hoping so, too. But there seems to be matrix in the middle. If we can determine this is indeed Arkona mud-shale, that would be a real game-changer, for sure. 

[doushantuo]

Pyrite or limonite,either way,it's iron

[westcoast]

28 minutes ago, doushantuo said:

Pyrite or limonite,either way,it's iron

That's a bit like saying chalk or gypsum, either way it's calcium 

[Guest11596]

2 hours ago, Kane said:

I think we've narrowed it down to Arkona Fm. Are there limonite traces there? Of course, without specimen in hand, I can't say for certain if it is set in some limonite. But you are probably pointing to the right tree to sniff up: the matrix in the centre of the whorl. That might be the key.

You would need to find a specimen in situ (on matrix). 

[Guest11596]

2 hours ago, westcoast said:

Loving this topic but not seeing the limonite that @middledevonian is seeing...looks like pyrite to me. Logic be damned I'm really hoping those sutures are Devonian. 

What I'm interpreting as limonite is outlined in yellow. I have not seen the specimen in hand so take it for it's worth.

 

[ynot]

11 minutes ago, middevonian said:

What I'm interpreting as limonite is outlined in yellow. I have not seen the specimen in hand so take it for it's worth.

My interpretation of that area is the original shell that is carbonized.

Just another opinion.

[Kane]

Our hope is in the centre. Notice how the whorl does not complete and shows off some matrix. We need to determine if the chemical composition is Arkona or something else. That's the only matrix this piece has. This is probably what will situate or not this piece in Arkona Fm. I would say a forensic analysis of what appears to be limonite on the right side should be done. If this is not a dropped specimen, this is truly exciting!

[Ludwigia]

There's been quite a discussion going on here since my last visit. Thanks for all your thoughts and contributions, everybody. I believe now that I've been leading us all on a wild goose chase and I'd like to apologize for that.

To quote myself: " I'm thinking more and more that it could have been dropped there, but one thing's for certain. It's not from me. Even if it was inadvertent and completely unconscious, I have never collected something like this in my life." I was so sure when I wrote that, but...

Kane asked again: " Roger, are you absolutely certain this didn't get mixed up with anything on your end (matrix debris)? I don't suspect that it is, but just to rule it out."

Well, I figured if there's a shadow of doubt, I might as well try to get to the bottom of this in order to rule it out. So I checked out all the possibilities from the sites I've visited in the past which might produce something like this and ended up at "the ditch" in the Kimmeridgian in the Danube Valley where I had a closer look at the sutures on the inner whorls of the ammonite species Aspidoceras acanthicum. Here they are.

 

 

And here's the whole specimen. You can see that the sutures get more and more complicated as the whorls progress.

 

What had me stymied is that the entire little "goniatite" is pyritized (and I believe that middevonian is also correct about the limonite), both of which are not all that common at this site. But it does occur more heavily at certain spots so the possibility is given. I remember that every once in a while I find some little things there and drop them in one of my collecting bags, so I guess that's what happened, and when I emptied my bag after the trip with Kane and mixed it up with the real goniatites, then the damage was done completely outside of my awareness.

Once again, I'm sorry to have caused such a tempest in a teapot, but I claim innocence due to ignorance. I certainly have learned a lot anyway and I'd like to thank everyone for their extremely helpful, knowledgeable and considered suggestions. This all really helped me to get to the bottom of it.

 

[doushantuo]

JEST love goose chases,the wilder the better

 

[FossilDAWG]

It's typical that suture lines will be a bit simpler in the earliest whorl(s) and become more complex in the more mature parts of the shell.

 

I think there is enough doubt about the provenance of this specimen to put it aside.  It's a good lesson for all of us to guard against cross-contamination between sites.  It's all too easy to carry over small fossils down in a corner or fold of a container or bag.  For those of us who enjoy microfossils, it's also important (and not easy) to make sure nothing is caught in our sieves and screens.

 

Don

[Kane]

Well, in science, sometimes a negative result is more informative. And, as Don says, it sounds a cautionary note about not mixing up stuff from different sites. In the end, though, this curiousity brought a lot of great people and their skills together, which is always heartening to see. The end result pales in comparison to the learning process seen here.  

[westcoast]

You have in fact reaffirmed the theory of evolution.

[Ludwigia]

I must say, I'm still embarrassed about this.  Im quite aware of the danger of cross-contamination, as Don puts it, which is why I generally turn my bags inside out and give them a good shake after they've been emptied, but I guess either I forgot to do this one, or else the little bu**er got stuck between the seams without me noticing it. At least I managed to track down my own mistake. Thanks again to everyone who took part in this.