What is the secret of the belemnite?

Discussion in 'Cephalopod Fossils' started by Phil, Jan 12, 2004.

  1. Phil

    Phil Colossal Squid Supporter Registered

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    Interesting new Magnetic Resonance Image scan of a belemnite revealing hitherto unsuspected spiral groove in the centre of the rostrum. Assuming that this is the siphuncle, does anyone have any theories as to why it would be spiral-shaped?

    http://www.globaltechnoscan.com/3rdApr-9thApr02/fossils.htm
     
  2. Phil

    Phil Colossal Squid Supporter Registered

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  3. Architeuthoceras

    Architeuthoceras Architeuthis Staff Member Moderator

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    Phil,
    Was there really a 5 meter Belemnoid :?: :!: :?: :!: :?: :!: :shock:

    As for the spiral shaped siphuncle, if the rostrum for some reason had a heavy spot (reoccuring) on one side, then the belemnoid would need to compensate. :?: Just a WAG :!:
     
  4. Phil

    Phil Colossal Squid Supporter Registered

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    Kevin,

    I must admit I have problems with the 5 meter length too. When I was researching the belemnite article the longest rostrum I could find referenced belonged to Megateuthis gigantea, a rare Jurassic European and Asian belemnite that had a rostrum measuring 50-60 cm in length. I suppose that one could surmise that the mantle would have approached 2 meters or more in length, and the total animal may well have been over 3 meters in length including the arms but it is difficult to be certain. Examples of this species have been from Luxembourg and 170 million year old specimens have been found in the Jura in Germany measuring almost 50cm.

    As for your rostrum idea, could be? I must admit though, I thought they were all symmetrical, but I could well be wrong. I didn't think the patternation in the siphuncle looked spiralled at all, to me it looked corrugated but is hard to tell from the image.

    Phil :onycho:
     

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