Dear Geoff, Markus and colleagues,
I think the fossil is a nematod, probably allied to the Chromadoridae. A
nice recent paper in Hydrobiologia by Verschelde et al. (2006, 571:17-40),
includes some SEM and drawing emphasizing the longitudinal keel.
Have fun,
Sergio
>From: Geoff Read <g.read from niwa.co.nz>
>Reply-To: g.read from niwa.co.nz>To: annelida from magpie.bio.indiana.edu>Subject: [Annelida] Fwd: Late Ordovician "worm"
>Date: Wed, 01 Nov 2006 08:19:22 +1300
>>Replies with taxa id suggestions to the list and to Markus Martin would be
>good.
>>Geoff
>>-------- Original Message --------
>Subject: Late Ordovician "worm"
>Date: Sun, 29 Oct 2006 22:48:19 -0500
>From: markus martin <brge.com from hotmail.com>
>To: <g.read from niwa.co.nz>
>>>>Dear Geoff,
>>My name is Markus Martin. I'm a vocational paleontologist currently
>excavating a conservation deposit of Late Ordovician shale in Northern
>New York. Most of my work centers on arthropods(trilobites) which are
>pyritized with preserved soft tissues and internal organs. However,
>I've come across several of these little "worms", for lack of better
>terminology. These specimens are incredibly preserved with fantastic
>detail, but all in all, no idea what they are! I do some joint
>research with Yale University and have passed specimens along. Everyone
>is at a loss of where to place these pesky little worms. I'm going to
>do a micro-ct scan if I ever get time which may shed some light.
>>I'm hoping you, or someone you know may be able to help! All specimens
>are 9mm-20mm and coiled. In the attached photo, note the stiff chord
>running the length of the specimen, as well as what appears to be the
>fanning out of the presumed tail region, and a strange attachment
>resembling a tube which sticks out a bit. The environment was benthic,
>90-180 meters depth, nearly anoxic and sulfur rich. I'm great with
>arthropods, not so good in this category!
>>Sincerely,
>Markus Martin
>brge.com from hotmail.com>>Markus later added:
>This 3D pyritized fossil of a soft tissue organism is about as good as it
>gets for 443 million years old. I don't expect anyone to shout a species
>name, but a few ideas would be a huge help. The deep water, nearly anoxic,
>benthic environment is a presumed one based on classically accepted
>theories of similar conservation deposits. However, the fauna coming out of
>these new shale beds suggest a much shallower higher energy ecosystem.
>There is the possibility that organisms such as this "worm" were
>transported from a shallower region during a massive storm surge.
>>The nature of the pyrite crystals themselves are framboidal(like little
>raspberries), which may suggest that there were sulfate reducing bacteria
>living in or on the organism and were active upon burial. This
>relationship could be chemoautotrophic in nature, if that occurs with
>annelids or nematodes as it does in some arthropods it could help in
>identification. This was an unexpected find and probably the most
>important one this year for us! Thanks for your help!
>>
><< IMG_1043.JPG >>
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