For Sale: Earliest known squid fossil and other cephalopods

Discussion in 'Cephalopod Fossils' started by michael schmidt, Feb 26, 2004.

  1. michael schmidt

    michael schmidt Blue Ring Registered

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    Hi

    I joined the list looking for any researchers who may be interested in a VERY rare squid specimen I have. I am a commercial fossil dealer, and I would very much like to see this specimen go to an institution. The info is below. If you can think of anyone who would be interested, please let me know. I do sell a very large amount of other cephalopod fossil materials, including material from Lebanon (I have a very nice specimen now), Germany, etc. I carry all types of fossils, and supply many other dealers on the net, so if you are looking for something specific, please let me know. here is the info on this French specimen:

    thanks


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    Gramadella piveteaui
    Name: La Voulte-sur-Rhône
    Location: Ardèche, France
    Age: Lower Callovian, Jurassic

    There were only 4 of these animals outside of French institutions. Three were auctioned last year and went to a US museum....not sure which one. I have the 4th one.

    It's really quite astounding......it's pyritised, and is wonderfully detailed. You can see the eyes, the tentacles...all of it. There is even a brittlestar on the plate. The specimen measures about 2" long and is completely inflated. Price is $6000 USD

    I am in the process of having professional pics done of it at school within the next few days. Here's an illustration:




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    Here's some info on the site:

    The fossils found at La Voulte-sur-Rhône are a Konservat-Lagerstatte, a deposit where the organisms show an unusual quality of preservation. In this case the soft parts are incredibly well preserved, sometimes down to cellular detail.

    The La Voulte-sur-Rhône Lagerstatte is found in several small quarries. These are all along the east west trending Ravin des Mines at La Boissine, to the west of the town of La Voulte-sur-Rhône in Ardèche in Southern France.

    Geological Setting
    Lithology
    The rocks at La Voulte-sur-Rhône are fine-grained, sedimentary rocks called silty shales, which contain pyrite (iron sulphide, FeS2). In some areas they are red due to the oxidation of iron minerals. Some horizons contain concretions (a calcareous or siliceous mass formed around an object), and others show simple horizontal burrows. The rocks of La Voulte-sur-Rhône have an unusually high metallic mineral content.

    Depositional Setting
    The sediment was probably deposited in a low energy, shallow marine basin. The water column was episodically stratified (no mixing of water at different depths).

    Evidence for low or no oxygen in the water

    The small number of local, bottom-dwelling organisms found at most levels.
    Horizons where everything died at the same time (mortality horizons) probably due to lack of oxygen.
    A turbidity flow (an underwater sediment flow driven by gravity) introduced organisms from a neighbouring oxygenated area (allocthonous fauna).

    The lack of plant matter indicates that deposition occurred far from land.





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    Age
    The Lagerstatte at La Voulte-sur-Rhône is Lower Callovian in age. This stage occurs at the end of the mid Jurassic, approximately 160 million years ago.





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    Fauna
    The fauna is divided into two very distinct faunas, allochthonous and in situ.

    The allochthonous fauna mainly consists of soft-bodied organisms which lived on the sea floor (benthic) or swam freely just above it (nektobenthic). It includes

    Worms
    Coleoid cephalopods including the world's oldest octopus and squid.
    Pycnogonids (sea spiders)
    Decapod, mysid and thylacocephalan crustaceans.
    Echinoderms such as crinoids (sea lilies), ophiuroids (brittle stars) e.g. Ophiopinna elegans, and other rare echinoderms
    Fish
    Marine crocodile Metriorhynchus
    This wide range of organisms found in close proximity on the surface of a bedding plane suggest that they were introduced by transport and were only together after death. None of the organisms was scavenged and none survived transport.
    The in situ mortality horizon consists of abundant pavements of a bivalve, Bositra buchi. It is likely to have been pelagic (lived in the open ocean) and the pavement was produced as they fell to bottom of the sea when they died. This was probably a result of anoxia (a severe reduction in the amount of oxygen dissolved in the water). The valves of their shells are still articulated (joined together) and spread open like wings.

    Trace fossils of in situ horizontal burrows are another indication of the presence of a local infauna (organisms which lived in the sediment).



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    The fossils at La Voulte-sur-Rhône show special preservation where the soft tissues have been preserved. They are found in two places, in concretions and in the shales surrounding them.

    Concretions
    Organisms are preserved three dimensionally and the soft tissues were replaced by a suite of minerals: - apatite, calcite, gypsum, pyrite, chalcopyrite, galena.

    These form a diagenetic sequence where the minerals replace and/ or coat the previous ones. As diagenesis progressed, more and more anatomical detail was lost.





    Diagenetic sequence


    Surrounding Shales
    The organisms are flattened and their soft tissues are replaced mainly by apatite and pyrite with the intervening areas filled with calcite.

    Thin layers of sediment found between the arms of cephalopods indicate that the allochthonous fauna was introduced by turbidity currents from an oxygenated area.

    The in situ bivalve (Bositra buchi) is still articulated. If they had been transported any distance the articulation would be broken. An anaerobic event killed them all off at the same time.

    Diagenetic minerals
    Apatite is the commonest mineral and is responsible for preservation of the greatest detail (individuals cells are still visible). It is only found on soft tissues that decay easily, such as muscle tissue. There is a decreasing gradient of phosphatization (apatite formation) from the outside of the muscle to the inside.

    Calcite replaces phosphatized muscle, obliterating the fine details of the muscle fibres and retaining only the gross morphology. Calcite also fills fractures in phosphatised muscle fibres.

    Gypsum sometimes replaces phosphatised muscle tissues instead of calcite. Replacement occurs in irregular patches unlike the smooth coats formed by pyrite.

    Pyritization occurs after phosphatisation, either at the same time or after the earliest stages of calcite precipitation. If there is too much pyritisation, detail is obscured. If there is too little pyritisation, the specimen disintegrates. Pyrite coats gut, gills, carapace and the phosphatised thick muscle fibres in crustaceans. Pyrite is the most important mineral for soft part preservation in squid and plants, and it replaces the valves of Bositra buchi.

    Chalcopyrite is a minor phase associated with pyrite.

    Galena replaces earlier mineralised tissues (especially if phosphatised) and preferentially develops on pyrite. It is only found in specific zones around fossils, and only preserves the gross morphology.


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    Fischer, J. ­C., and Riou, B., 1982, Les Teuthoides (Cephalopoda, Dibranchiata) du Callovian Inférieur de La Voulte-sur-Rhône (Ardèche, France): Annales de Paléontologie (Vertebrés-Invertebrés)


    Wilby, P. R., 2001, La Voulte-sur-Rhône: p. 349-351, In Palaeobiology II, eds Briggs, D. E. G., and Crowther, P. R., Blackwell Science.

    Wilby, P. R., Briggs, D. E. G., and Riou, B., 1996, Mineralization of soft-bodied invertebrates in a Jurassic metalliferous deposit: Geology, v. 24, p. 847-850.
     
  2. willsquish

    willsquish Blue Ring Supporter

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    Hello,
    sorry for such a late reply. Are you still around, and do you have a picture?
    --Will
     
  3. forbidden_moose

    forbidden_moose Pygmy Octopus Registered

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    Are these still up for offer
     
  4. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    Unlikely, the original offering post was in 2004.
     

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