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Ultra Rare Spiny Helically-coiled Heteromorph Ammonite

$18,000.00 USD

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This item has sold. Please inquire if you are looking for a heteromorph ammonite or spiny ammonite.
  • This immaculately preserved and expertly prepared ammonite with remarkable shell structure is incomparably rare. Unlike most ammonites, which coil along a single plane, it belongs to a bizarre group of prehistoric cephalopods known as "heteromorph" ammonites, which have uncoiled or irregularly coiled shells.

    The shell of this rare and unusual species (Ostlingoceras puzosianum) is lined with spines (which, incredibly, have been preserved), and has a partially fused helical ("corkscrew") shape, similar to many bottom-dwelling Gastropods (snails). Unlike Gastropods, however, the internal structure is multi-chambered like all ammonites.

    Without a doubt, this is the greatest ammonite fossil we have come across, and we highly recommend it as an investment fossil. This is an absolutely once-in-a-lifetime find from a fossil locale that boasts some of the rarest and most interesting ammonites ever discovered. In addition to the incredible array of spines, this specimen has a preserved apertural rostrum (the hooked process at the open end) - this feature is extraordinarily rare and virtually never fossilizes at all due its delicate nature. 

  • This museum quality Ostlingoceras specimen was discovered and prepared by a renowned fossil preparator and collector who specializes in heteromorph ammonites from France. Over 200 hours of painstaking work was needed to expose the three-dimensional form of the fossil from the matrix. Many spines were distributed in the surrounding matrix and had to individually prepared and re-glued into   The specimen's original position has been precisely maintained so that nature’s beauty can take centre stage in this scientifically significant and aesthetic fossil.

    Species: Ostlingoceras puzosianum
    Age: Albian Stage of the Lower Cretaceous - 108 million years old.
    Location: Alpes-de-Haute-Provence, Southeastern France.
    Dimensions: Specimen measures 12.25 inches (length) by 3 inches diameter at top, by 1.9 inches thick. Matrix measures 12 x 13 x 3.5 inches.

  • Restoration notes: 80% of the spines are original (20% were cast), and some were found in the associated matrix and re-glued into their original anatomical position. Note that spines rarely fossilize, are incredibly difficult to prepare and some likely wore off during the ammonite's lifetime. All of the whorls are original; i.e., it is in fact a complete specimen. We will provide documentation verifying the authenticity of this truly museum-quality specimen.