Unknown belemnitid/belemnotheutid, Upper Lias, Yorkshire

Discussion in 'Cephalopod Fossils' started by Nannobelus, Apr 24, 2015.

  1. Nannobelus

    Nannobelus Pygmy Octopus Registered

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    I've just collected this large phragmocone with tiny rostrum from the Falciferum Subzone ("Bituminous Shales") near Whitby. I've been collecting and studying belemnites and other coleoids for decades but haven't seen another like this from the Yorkshire Lias (or anywhere else, really) before.

    It's belemnotheutid like in that it has a small rostral apex, the rest of the rostrum apparently being a thin layer over the end of the phragmocone. Chondroteuthis wunnenbergi from the Alderton Fish Bed is the nearest I can find in the literature. The apical angle of this one is much larger though, about 45 degrees in the crushed state so roughly 30 degrees uncrushed.

    The wide phragmocone resembles Phragmoteuthis and Clarkeiteuthis but they don't have a rostrum.
    It is also reminiscent of the belemnite Coeloteuthis.

    Length: 12.5cm
    Max. width: 7cm
    Rostral apex, photographed separately befor regluing: 6mm long.

    Any suggestions gratefully received! - anything like it from the Posidonienschiefer perhaps?

    IMG_1278.jpg

    IMG_1279.jpg

    6mm rostrum apex
    IMG_1273.jpg

    rostrum section showing septa
    IMG_1272.jpg
     
  2. Architeuthoceras

    Architeuthoceras Architeuthis Staff Member Moderator

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    Wish I could help. Looks like a nice fossil, unfortunately I have little experience with coleoids like this.
     
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  3. cuttlegirl

    cuttlegirl Colossal Squid Supporter Registered

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    Cool!
     
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  4. Nannobelus

    Nannobelus Pygmy Octopus Registered

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    Thanks for looking!
     
  5. DWhatley

    DWhatley Cthulhu Staff Member Moderator

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    I've asked @Hajar to have a look after he recovers from his jet lag.
     
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  6. Nannobelus

    Nannobelus Pygmy Octopus Registered

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    Many thanks, I was hoping he was still around!
     
  7. Hajar

    Hajar Haliphron Atlanticus Registered

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    It's a wonderful find!

    I forwarded the post to Dirk Fuchs, expert on fossil coleoids, and I'm sure he will be able to help (as for me, after a day off, it's back to the airport. I'll browse the literature next weekend - the last paper I remember reading on Yorkshire coleoids was Doyle 1990, quite a long while back).
     
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  8. Nannobelus

    Nannobelus Pygmy Octopus Registered

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    Thanks very much, Hajar, that's brilliant. I've read several of Fuchs' papers and he's certainly an ideal person to look at this, hope he's interested.
    I should perhaps ask Peter Doyle too - as well as his 1990 teuthid paper, there's Doyle & Shakides, 2004, on Belemnotheutina, which has some possibly related material.
     
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  9. Hajar

    Hajar Haliphron Atlanticus Registered

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    So (from another airport), here's what Dirk says:
    "I agree with "Nannobelus" that belemnoids with a sheath-like rostrum (Phragmoteuthis, Chondroteuthis, Clarkeiteuthis) can be excluded.
    I talked to Robert Weis from Luxembourg and he also agrees that these specimens are closest to Coeloteuthis."
     
  10. Nannobelus

    Nannobelus Pygmy Octopus Registered

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    Many thanks, Hajar, and to Dirk and Robert, that's very helpful.

    So probably a coeloteuthine belemnite, although I think something belemnotheutid like is still a possibility.

    The rostral preservation in the broken section doesn't show radiating belemnite-type crystal structure and may be aragonitic - it looks similar to belemnite epirostrum sections from the same beds.

    With the specimen in hand, it seems there is a large, thin rostral sheath anterior to the apical bit - of course, ordinary belemnites show that as well when they're complete enough.

    More material would be nice - I can't believe these haven't turned up before.

    (I'm TqB, Tarquin, from other forums by the way - we've exchanged comments before, your coleoid collection is very fine!)
     
  11. Nannobelus

    Nannobelus Pygmy Octopus Registered

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    Just tried to edit that but its time expired - what I wrote above sounds a bit ungrateful - not my intention at all! I wanted to say that a coeloteuthine belemnite from these beds would be quite exciting, not heard of any before!
     
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  12. tonmo

    tonmo Titanites Staff Member Webmaster Moderator

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    I just checked the setting... 5 minutes to edit a post isn't very generous! :smile: I upped it to 60 minutes. (note, Supporters are unlimited... this is to contain bad behavior; otherwise people could go back to old posts and try to edit them to add in spammy links)

    For what it's worth you didn't seem ungrateful to me :smile:

    Great pics!
     
  13. Nannobelus

    Nannobelus Pygmy Octopus Registered

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    Thanks, Tony!

    I'm still leaning towards this being a belemnotheutid type of coleoid (Belemnotheutis, Chondroteuthis).
    Coeloteuthis Lissajous, which has to be interpreted according to the lectotype of Belemnites excavatus Phillips, is a "normal" fat belemnite, and doesn't seem to be very similar to this specimen.
     
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