Triassic Nautiloid Pearl Blister

Discussion in 'Nautilidae' started by SteveM, Jun 15, 2011.

  1. SteveM

    SteveM Blue Ring Registered

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    In a broad search for precedents to substantiate modern-day Nautilid pearls, extremely rare paleo-pathological work has been of great interest. Attached from an obscure monograph (thanks to Princeton University for an excellent scan) is a Pleuronautilus pseudoplanilateratus (Kieslinger, 1916), Middle/Late Triassic (200+MYA) from Timor, Indonesia. Alois Kieslinger was in his immediate post-doctorate career when traveling as a member of the 1916 Dutch Timor Expedition, later to become associated with research into stone monument preservation, including the Parthenon in Athens.

    What is of extreme interest to me is the incredible similarity of shell morphology between the Pleuronautilus and N. Pompilius (note how Kieslinger's figure and a modern Nautilus shell section match coils perfectly, showing the body chamber location of the pearl blister). Even the most optimistic research (unpublished, P. Ward) has modern Nautilus appearing only as early as the late Mesozoic.

    Kieslinger's Pleuronautilus is a dead ringer for the mysterious Allonautilus Perforatus, known only from drift shells and (along with A. Scrobiculatus) thought to be the most recent evolution of Nautilida.

    Will be very interested to discover the differences between this Triassic Nautiloid and modern Nautilus shells.
     

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  2. Architeuthoceras

    Architeuthoceras Architeuthis Staff Member Moderator

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    :welcome: to TONMO SteveM,

    The perforate umbilicus and the more vertical and flat umbilical wall of Pleuronautilus stand out to me, the ribs a little less so.

    I am leaving in the morning for ten day of field work, hopefully I can look into this a little more when I return.
     
  3. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    As in work WORK or as in fossil fun?
     
  4. SteveM

    SteveM Blue Ring Registered

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    Many thanks for the welcome, and happy hunting. A good image of A. Perforatus should be posted here, I have Ward/Saunders 1997 on my office computer, which I will not be able to access until return from travel July 05.

    I will also try to detail in due course Peter Ward's latest work pushing back the modern genus Nautilus to well below the KT boundary (albeit remaining 100MY distant from upper Triassic).
     
  5. Architeuthoceras

    Architeuthoceras Architeuthis Staff Member Moderator

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    Fossil fun :grin: Hopefully there will be a few updates during the week.

    See HERE for some Devonian cephalopod pearls
     
  6. SteveM

    SteveM Blue Ring Registered

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    Yes, De Baets et al received a huge amount of popular press with this a few months back. Work directly related to House, and Mapes (the paper's primary reviewer). What an incredible parasite infestation was occurring in Moroccan waters at the time! But these are shell blisters, not pearl blisters, and have not given us much of a hint regarding the theoretical formation or composition of loose Nautiloidea pearls.

    De Baets does offer an enticing citation from the work of Helmut Keupp. I was lucky enough to get in touch with Prof. Keupp to obtain an otherwise unavailable paper of his from 1986, and he mentioned that he is currently working on a summary paper concerning Nautiloid/Ammonite paleopathology. More to come!
     
  7. SteveM

    SteveM Blue Ring Registered

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    Scanning my laptop in vain for the aforementioned A. Perforatus image, I did find these images to add to this discussion:

    1) Side and apertural views from Kieslinger of the Timor Late Triassic Pleuronautilus with pearl blister.

    2) Modern N. Pompilius shell (also from Timor!) with a similarly-located pearl blister, plus a curious reinforcement of the final septal suture that happens to correspond precisely with an exterior shell fracture. Would be curious to know of any similar experience.
     

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  8. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    Do pearls leave indentations in oysters (and/or clams) of modern day animals? Given Kevin's reference that they likely originated as attached parasites rather than grains of loose sand I assume not (nor have I seen internal pits but I have not found a lot of pearls in my mollask consumption.
     
  9. SteveM

    SteveM Blue Ring Registered

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    As I just arrived here (via pearls, via Nautilus) and cannot readily find the reference to Kevin, will just jump in although the thread goes off its tracks. CORRECT that pearls do not arise from grains of sand, a scientific impossibility as sand is anything but an irritant to a mollusk. But what a persistent myth it is.

    Shell blisters arise from the mollusk reinforcing its interior shell to ward off parasitic attack. Cysts (pearl sacs if composed of mantle epithelial cells) arise from irritation by parasite or injury, resulting in loose pearls. In fact pearl sacs that abutt the shell without being expelled or attached to the shell do often result in an indentation as the shell continues to grow around the protuberance, leaving what amounts to the ultimate pearl provenance—a matching bed. This is quite the hot item among rare pearl collectors these days—a rare pearl species together with its undeniable shell of origin.
     
  10. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    I guess I am glad we are roughly the same age :grin: younger people might have thought I was totally crazy (of course they might anyway :wink:) for the "well known" understanding of how pearls begin. Now that you have freed that piece of memory for other knowledge, how do they seed cultured pearls?

    Sorry, Kevin is Architeuthoceras. I will move these three post to your original Triassic Nautloid Pearl Blister thread for continuity (Post #5). He gave me a reference to read on Nautiloid Pearls when I wondered about the possibility of ingestion rather than creation.
     
  11. SteveM

    SteveM Blue Ring Registered

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    Welcome the opportunity to free another neural region of a little detritus.

    The process stolen and thereafter perfected/patented by Koichi Mikimoto in the early 20th century involves surgical creation of a pearl sac by inserting a small piece of mantle tissue into the flesh of the animal (grafting), thus assuring that a cyst is formed of mantle epithelial cells producing the same aragonite microstructure as the inner lining of the shell (most commercially: nacre/mother of pearl). The primary objective is round shape, so uncommonly found in nature. To guide the shape and guarantee pearl size, a round shell bead is introduced at the same time as the mantle tissue. The bead is then coated with the shell material, resulting in an inverted shell (exterior within, interior without). Eventually it was discovered that insertion into the oyster's gonad would doubly assure that the sac would become round, the gonad also serving as a less surgically-sensitive organ.

    The success of this model literally destroyed the natural pearl business by the mid-20th century (not to ignore overfishing by a new generation of pearl divers with air supply), as women could obtain perfectly round and shiny 'pearls' at a tiny fraction of the price Indian Rajahs and robber-baron matrons traditionally paid for the real thing. But in the end, such 'pearls' are nothing more nor less than nacre-coated beads in the eyes of the purist.

    Mantle tissue without the guiding bead is also done, typically resulting in baroque pearls known as keshi, although the Chinese freshwater mussel pearl industry has perfected its grafting technique to the point that the bead is no longer necessary to obtain symmetrical shape.
     
  12. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    This is a very dangereous topic :grin:. I have the feeling that "real" pearls, from whatever animal makes them are not in my hobby budget and I am not likely to find any on my own but more reading is tempting. Is there a visual (ie with only the eye) way to distinguish cultured pearls (I assume the term is still correct?) and natural ones? Using commonly available (more or less) tools, would weight per diameter be an indicator since the inside of a cultured pearl does not contain the same material?

    Lastly, to ensure we stay on topic, what cephalopods (as I mentioned I saw the one octopus pearl) produce pearls today and which are suspected of producing them in the past. Of the ones found today, is there an area of the world where they are most common?
     
  13. SteveM

    SteveM Blue Ring Registered

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    First of all, 'pearls' (read: 'concretions') are innate to all organisms as anomalies. On topic, true pearls are calcium carbonate biomineralizations from shelled mollusks. Dave LeBlanc's octopus pearl is certainly an anomaly, but holds some intrigue for the concept of latent ectocochleate genomics of Cephalopoda.

    The only Cephalopod pearl in the literature is Nautilus (albeit unsubstantiated scientifically—my current challenge), and of course the geographical restrictions would match Nautilus/Allonautilus habitat. Regions with particularly strong cultural/mythical regard for Nautilus pearls are the Sulu Archipelago in the Philippines and nearly all of Indonesia. Then there is the one Arthur Willey claimed to have found in 1896, in the Bismark Archipelago.

    By international agreement, 'pearl' is a word that may only be used commercially for natural, or wild, pearls. Cultured pearls sold without the qualifier are not legal tender, under FTC restrictions. For telling natural pearls from cultured without technology, nearly impossible without experience (thus the commercial success of pearl culturing). The bead used in culturing is mussel shell nacre with the same density. Gemological laboratories with great depth of experience and a battery of sophisticated equipment certify natural pearls for the collector and investment community, and as you might imagine there are shady types that go to any lengths to confuse them—requiring ever greater technology. Very much akin to the tit-for-tat that goes on in the computer virus world.
     
  14. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    It would seem that someone would have "seeded" a nautilus to see if it produced a pearl. The thought assumes the process would be similar to seeding mollasks. The animal would have to live long enough to allow growth (a challenge in an aquarium) and seeding could only validate (but not invalidate) the potential but it seems like an obvious experiment.
     
  15. SteveM

    SteveM Blue Ring Registered

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    The results of culturing a Nautilus blister are highly predictable, and are already known from the natural blisters found in anomalous shells and fossils. This does not help us to explain the highly unusual composition of putative Nautilus loose (whole) pearls, which appears to have something to do with the unique and periodic biomineralization process of the inaccessible rear (septal) mantle. The hope at some point is that there will be enough phylogenic-related scientific curiosity to pursue this aside from commercial considerations. Besides, can you imagine the physical plant required to farm 100s if not 1000s of Nautiluses to make a go of pearl production on a commercial scale…
     
  16. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    Sorry for my lack of background. Is it both the free form (not blistered) and material being non-nacre that is the curiosity and linkage or just the non-nacre substance?
     
  17. SteveM

    SteveM Blue Ring Registered

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    D.,

    Join the club. It's only been a few days since I brought this to the attention of TONMO, so it is only natural that folks here would desire a ready resolution. We've been at it for nearly four years now.

    All that is known is that the pearls in question are indeed non-nacreous natural aragonite pearls from a saltwater mollusk, claimed by Indo-Pacific pearl traders as Nautilus with no reasonable alternative. They are certainly rare, and certainly fascinating (my avatar). It was just one year ago at the University of Granada that their Paleozoic (and modern Monoplacophoran) aragonite microstructure was observed, since reconfirmed by state-of-the-art crystallographic analysis. This has brought some pretty significant scientific minds to bear, but the serious work is just getting started.

    I refer to the mystery mollusk—until such time as pearl linkage should somehow be confirmed—by the tongue-in-cheek taxon 'Molluscus Abominabilis' (M. Abominabilis). Nautilus or 'Naut', these pearls offer some pretty amazing theoretical challenges. And they have opened my completely untrained eyes to the world of Cephalopoda, Paleontology and TONMO!

    P.S.: If these pearls are indeed Nautilus, this will only be determined via a thorough, even unprecedented, investigation of Nautilus biology. The pearl experts are of very little use at this point…
     
  18. Pr0teusUnbound

    Pr0teusUnbound GPO Registered

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    interesting!
    ive heard of similar formations in fossil goniatite and ammonite shells. the pearls were usually smaller, more flush with the shell surface and found on the lateral and ventral lining of the body chamber.
     

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