Gleviceras – a small Riparioceras in a big cloak

 

Gleviceras at Robin Hoods Bay is very rare – at least for me – to the point that I do not have much more than a small bit of a whorl, found at the time of the rebuilding of the sewage pipe (link) on May 1, 1996, a small bit of Gleviceras subguibalianum, from the upper Sinemurian, aplanatum subzone, Robin Hoods Bay  which is not really representable, and as usual, if you have a better one from the area, let me know !

 

The following is a Radstock/ Somerset specimen to show you what a whole Gleviceras looks like :

 
Gleviceras sp. from Radstock / Somerset, 17 cm, inner whorl not preserved

Gleviceras sp. from Radstock / Somerset, 17 cm, inner whorl not preserved

 

So did you wonder what I meant with the title of this post ?

 

Well, the astounding thing about Gleviceras is, and allthough I´ve had some discussion about it with a regular reader of this blog (that´s you Joe !) in 2012,
I’ve only relatively recently become really aware of this through Mike Howarth’s Treatise #57 volume, even as it looks very much like a member of the
Oxynoticeratidae family that it is from the outside, it starts as a tiny “Riparioceras” on the inside.

 
A 3.5 cm Gleviceras sp. from Gloucestershire shows where the journey is going...

A 3.5 cm Gleviceras sp. from Gloucestershire shows where the journey is going…

 

If you had found a pyrite “Riparioceras” at the usual size of e.g. max. 1-2 cm you’d be well excused to think that this could never,
ever develop into a Gleviceras like shown from Radstock above, and I would certainly have thought the same.

 

That is, before I saw final living (actually quite long dead) proof in this Dorset specimen on eBay below :

 
 

It is not the finest preservation that can be found, but it is just eroded enough around the umbilicus to reveal its “Riparioceras” state beginning,
something you would not see in the un-eroded state – I just had to get it, see it with my own eyes and show you…

 

Gleviceras BUCKMAN 1918 has precedence over Riparioceras SCHINDEWOLF 1962, so that “degrades” Riparioceras to a synonym for Gleviceras.

 

Just shows again, a species should never be erected on the basis of non-adult specimen only…

 

AndyS

Leave a comment

2 Comments

  1. Great post, Andy, thanks for sharing. I’m glad that you solved that mystery, and that specimen is the perfect way to demonstrate it. How’s the rest of the book going? Are you still hoping to publish it later this year?

    Kind regards,

    Joe

    Reply
    • Thanks Joe, I´m still hoping to get it done at least from a photographing / editing standpoint.
      All the best,
      Andy

      Reply

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: