Pathological ammonites

Discussion in 'Cephalopod Fossils' started by neuropteris, Jun 25, 2004.

  1. neuropteris

    neuropteris GPO Registered

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    Hello all

    This is my first attempt to post an image so apologies if it all goes pear shaped.

    The pic is of a Dactylioceras commune from Port Mulgrave on the Yorkshire coast. Found it earlier this year and took it into work to demonstrate how to pop a nodule to my colleague (with the promise to let here have it if it came out nicely). Needless to say I had to reclaim it when I saw the deformation :bugout: (Gave her a more perfect and therefore less interesting one in exchange)

    Anyone have any ideas what could have caused the groove running through the second whorl? Its pre mortem and seems to have healed.

    Best regards

    Andy[/img]
     
  2. Phil

    Phil Colossal Squid Supporter Registered

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    Hi Andy and :welcome: to TONMO. Always good to have another fossil collector around here. Thanks for posting your ammonite find, nice specimen.

    To be honest, I really have not got a clue what could have caused the scar. I'm just guessing here but could this have been damage to corresponding section of the edge of the fleshy mantle that left a residual scar on the shell as it was slowly secreted? Perhaps the wound repaired itself over time allowing normal formation of the shell in the outer whorls. It would be nice to think it was predation damage but I don't think that could be determined easily.

    Kevin might be able to help here.....

    Please post any details of cephalopod fossils you have found. I'm sure we would like to see them, especially natural snakestones! :)

    Phil

    :ammonite:
     
  3. Architeuthoceras

    Architeuthoceras Architeuthis Staff Member Moderator

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    :welcome: to TONMO Andy,

    DISCLAIMER: I am not a Doctor, I just play one on TONMO :!:

    Looks like your ammonite had a common case of "Forma verticata" brought on either by injury or parasitism, causing local dysfunction of the mantle, which caused the scar. Ref: Rainer Hengsbach, Ammonoid Pathology, pp. 581-602: in Landman et. al., 1996, Ammonoid Paleobiology, Plenum Press.

    I think damage made by a predator would be more severe, causing a larger break and a larger scar. Just having a small portion of the mantle disfunctional would be more likely caused by parasites, a small collision, or maybe a sand grain or something stuck between the mantle and the shell.
    Great fossil, thanks for posting the pic.
     
  4. neuropteris

    neuropteris GPO Registered

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    Thanks for the info. Dac commune is very common on the Yorkshire coast so I must have seen a few hundred. I've found them with smooth bumps and distortions before but nothing so drastic as that one.

    I've been collecting on the coast for a few years now and have managed to obtain a variety of ammonites so I'll dust off the camera and take a few more snaps.

    Also, the green blotches on the picture are an artifact of the image - not my poor cleaning methods! My carpet seems to have gone a funny colour to.

    Best wishes

    Andy
    Proud to be a Larval Mass!
     
  5. AndyS

    AndyS Cuttlefish Registered

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    Interesting topic this one, so I had to step out of my lurking in the background. Here come two of the most prominently pathological ammonites from my collection :

    The first picture shows a "Twoface" Hildoceras from Ravenscar, Yorkshire coast. It has two completely different sides, one side has lost the typical groove completely, the other side shows a typical Hildoceras sculpture.
    (Followers of the discussions on ukfossils will know the story on this one)

    The other pictures show different views of a Pleuroceras paucicostatum from Hawsker Bottoms, Yorkshire, that has at one point "inverted" its keel, size is about 3 inches.
    Mother nature shamefully hid the point where the deed was done by eroding off that exact part of the whorl, but you can nicely see that before that point it had a normal keel, afterwards the keel is "inverted". The ammonite must have happily lived with that structural deviation, since the inversion shows on the last half whorl of the ammonite, covering the whole living chamber.

    Would be interested to see other examples of pathological ammonites as well.

    Best regards,

    AndyS
     
  6. Architeuthoceras

    Architeuthoceras Architeuthis Staff Member Moderator

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    :welcome: AndyS,

    These both seem to be the same form of pathology as the other Andys'.

    The scar on the Hildoceras looks like it lasted right up until the ammonoid was mature.

    Too bad the starting point of the scar on the Pleuroceras is gone. it would be nice to see how the keel inverted.

    It seems the only pathology on any of my ammonoids is "Post-Mortem" . However, every one of the Mitorthoceras (orthoconic nautiloid) fossils I have, shows damage and repair to the shell at several locations.
    [​IMG]
    Orthocone Pathology
     
  7. spartacus

    spartacus Haliphron Atlanticus Registered

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    Good day to you Andy and AndyS and willkommen,
    Mine too Kevin, along the lines of BFH & questionable aptitude :( & I'm surprised at Phil :roll: he'd normally produce a photo of the event.

    I take it we're working on the lines of BFH meets thumb producing deformed thumbnail :cry: scenario ? Kevin has ruled out any pliosaurian intervention & stop me if I'm wrong but I can't see any teuthid gladius damage or fragments so "squid choking" can be ruled out.

    Cometary impact anyone ?

    Phil, all the snakestones are gone ! St. Hilda Ogden killed them all dammit :evil:
     
  8. Architeuthoceras

    Architeuthoceras Architeuthis Staff Member Moderator

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    After further study, and a view of a healthy specimen. (Thanks Andy) I can revise the two-faced pathology of AndyS' fossil.

    The Hildoceras probably has a form of "Forma Circumdata", when the shell producing part of the mantle where the groove was supposed to be wasnt functioning, the ventral, rib producing, part of the mantle was stretched over and took over the shell producing function, causing ribs to be formed all the way to the umbilical seam.

    Good thing these ammonites are long dead, they don't need to seek a second opinion, or even pay me, or file suit. :lol:
     
  9. AndyS

    AndyS Cuttlefish Registered

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    Kevin,

    Thanks for the IDs and the ammonoid palaeobiology reference, seems to be a good book but at a hefty price ! :?
    I have another one here, this time it is an Asteroceras obtusum forma juxtacarinata, found some time ago by a friend at Robin Hoods Bay in Yorkshire, he gave me a cast as a birthday present.
    The keel is not at it's usual place but has wandered from the venter towards the flank. The mechanism is probably the same as you described for the Hildoceras, just this time it is more obvious, since you can still see on the inner whorls that it used to be quite normal.

    AndyS
     
  10. Architeuthoceras

    Architeuthoceras Architeuthis Staff Member Moderator

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    Thanks for another great pic AndyS. Yes the book is quite expensive, I ordered my copy before publication, so I got it about 1/2 of the present price.

    Has anyone seen, or know of, pathologic ammonites other than Jurassic in age? Was there an epidemic in the jurassic, or are there just more ammonites from jurassic rocks to increase the odds of finding pathologies? Is it just that parasitic pathologies are more common in jurassic ammonites?

    :?: :?: :?: :?:
     
  11. Phil

    Phil Colossal Squid Supporter Registered

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    Very interesting discussion. I have two and a half questions for you:

    1) Is it possible to differentiate between parasitic and fungal infection in ammonoids?

    2) Has parasitic distortion of the shell been observed in Nautilus?
    If so, is the modern Nautilus an appropriate baseline for comparison? Or do the differences in conch morphology not allow for a direct correlation?

    Phil
     
  12. spartacus

    spartacus Haliphron Atlanticus Registered

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    I'll sit this one out if you don't mind :grad: I may learn something if I shut-up. :D
     
  13. Architeuthoceras

    Architeuthoceras Architeuthis Staff Member Moderator

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    Phil said Fungal 8)

    That is the first time I have ever seen the words fungal and ammonoid used in the same sentence. Of coarse the fist time I really saw parasite and ammonoid in the same sentence, was just after this thread started. I was just starting to get a grip on the difference between injury and parasitic/"fungal"/viral/biologic.
    This is all a long way of saying I dont know! :)

    Nautilus kept in captivity produce a discolored and distorted shell...Fungal/parasitic :?:

    Injury and repair is usually obvious, a jagged edge with new shell and ornamentation picking up where it left off, only offset. A parasite would probably cause a longitudinal scar that would last until it was extirpated. What would a fungal infection look like?

    More study is needed, unfortunately I really must get back to work now :(
     
  14. spartacus

    spartacus Haliphron Atlanticus Registered

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    Kevin, it is time for me to speak as I've just learnt something

    pukka new word logged & ready for use :notworth:
     
  15. Phil

    Phil Colossal Squid Supporter Registered

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    OK, I could swear I saw a reference to this a couple of days ago, hence I posted the question. :? Typically, I am damned if I can find the reference now, despite extensive searching. Best forget I mentioned it unless I can turn up something substantial!

    :bonk: (I've confused myself now....) :ammonite:
     
  16. Carl J. Bobrow

    Carl J. Bobrow Blue Ring Registered

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    Nautilus deformation "black shell syndrome"

    Good day all, a bit of information and more to come on the topic when I have my notes and images in front of me. The Nautilus seems to develop quite quickly in captivity this may be due a variety of factors. One of the many symptoms of captivity is the deformation of the shell "black shell syndrome.” I will post some images when I get the chance. These may be stress related due to water chemistry, lack of vertical migration (pressure change), food, light etc... The natural environment of the Nautilus is at mid depth on the reef shelf 200ft and below. Therefore, changes in shell development are to be expected but some of them are rather startling. The pathology report done at the National Zoo to one of the Nautilus which died a few years back as well as pathology on living specimens do not indicate infection or hosts as the result although there are host living opportunistically in the locality of the deformation. So the best guess is... environmental factors are at play causing abnormal shell development.

    More to come

    Regards

    Carl


    :grad:

    PS:if you want to find a wonderful text, Treatise on Invertebrate Paleontology, which includes three volumes on Cephalopods (only two available) try these sites locations

    http://www.ku.edu/~paleo/treatise.html

    http://rock.geosociety.org/bookstore/default.asp?oID=0&catID=13&rslID=2

    http://rock.geosociety.org/bookstore/default.asp?oID=0&catID=13&pID=TREK
     
  17. Architeuthoceras

    Architeuthoceras Architeuthis Staff Member Moderator

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    Thanks Carl,

    Do you know of any parasitic shell deformation in wild Nautilus shells? I seem to recall that Peter Ward broke some Nautilus shells just to see how they repaired themselves and what affect it had on their bouyancy, but I cant remember anything about parasites.

    And thanks for the heads up on the treatise.
     
  18. Carl J. Bobrow

    Carl J. Bobrow Blue Ring Registered

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    Nautilus shell reply

    Thank you for the question and the reminder, I posted the mail from work and forgot to add the obvious. The American Museum of Natural History has a wonderful collection of Nautilus shells. Dr. Landman has permited me on occasion to examine these (no big deal really) and what we found was that in fact in the wild Nautilus do exhibit the shell deformation that is common or ever present in captivity. Though I am not sure about those kept at Palau (need to check on this). So it seems that this is a natural state for some reason for some Nautilus the big question is why. One of the things on my list of things to do is to check the collection at the Smithsonian, when I get the chance to breath, and see what they have.

    As a side bar I think that the Spirula Spirula has been overlooked and I am trying to avocate a more intensive study of them, perhaps a good Phd. project for someone, I wish I had the time to do it! :bugout: hahahahaha

    more later and pix to I promise

    CjB

    "freedom from tyrrany"
     
  19. Architeuthoceras

    Architeuthoceras Architeuthis Staff Member Moderator

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    Looking closer at some of my fossils, I found this Eosyngastrioceras hesperium (Late Mississippian, Arnsbergian Stage) with a small pathology

    Top Picture:
    Lateral and ventral view, the pathology is on the right side of the ventral view


    Lower Picture:
    a closeup of the pathology
     

    Attached Files:

  20. Carl J. Bobrow

    Carl J. Bobrow Blue Ring Registered

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    Bite marks!

    :madsci:


    This is exciting, well sort of I suppose.

    A quick note and I trust others will confirm my opinion, the "nick" or "grove" exhibited in the pic (previous post, good shot too) is that of a predatory bite. You can view such "blemishes" on modern day Nautilus shells, they are often attributed to Octopus bites (P.D. Ward etc...).

    I know I promised some images on deformed Nautilus shell and I will. Although I loath excuses here is the current one, these pics live on my sons computer at home and I have had little time to log on in the evening due to travel and work at the Smithsonian. I will get these out as well as some additional images of the bite marks on Nautilus shells for comparison.

    Regards

    CjB
     

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