Confusion About Ammonite Anatomy Terms

Discussion in 'Cephalopod Fossils' started by Pr0teusUnbound, Nov 23, 2012.

  1. Pr0teusUnbound

    Pr0teusUnbound GPO Registered

    Joined:
    Nov 6, 2012
    Messages:
    128
    Likes Received:
    32
    there are a few ammonite shell anatomy terms that have been confusing me.

    what do the terms "whorl" and "volution" mean? are they the same thing? are they a full revolution shell growth (360 degrees?) around the unbilical axis? or just 3/4 (270 degrees?) around it?
     
    tonmo likes this.
  2. Architeuthoceras

    Architeuthoceras Architeuthis Staff Member Moderator

    Joined:
    Nov 19, 2002
    Messages:
    2,391
    Likes Received:
    94
    Location:
    somewhere under the desert sky
    I think they can be used for the same thing... Whorl more like a noun, or referring to the shell, and volution more like a verb, referring to growth. Both refer to 1 complete revolution.
     
    tonmo and Terri like this.
  3. Pr0teusUnbound

    Pr0teusUnbound GPO Registered

    Joined:
    Nov 6, 2012
    Messages:
    128
    Likes Received:
    32
    really? i remember reading somewhere that a volution was 3/4 of a complete revolution (supposedly because the final quarter of the revolution was larger than each previous quarter).
     

Share This Page