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derbyshiredowser
Joined: 11 Feb 2007 Posts: 806 Location: derbyshire
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Posted: Fri Jul 06, 18 10:05 am Post subject: Beach find |
 
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Found this on the beach at Porthmadog last week and wondered what it was ,can't find it in any books , Thanks |
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sean Downsizer Moderator
Joined: 28 Oct 2004 Posts: 41939 Location: North Devon
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Posted: Fri Jul 06, 18 11:06 am Post subject: |
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Some sort of sea urchin? |
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Hairyloon
Joined: 20 Nov 2008 Posts: 15151 Location: Today I are mostly being in Yorkshire.
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buzzy
Joined: 04 Jan 2011 Posts: 3456 Location: In a small wood on the edge of the Huntingdonshire Wolds
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derbyshiredowser
Joined: 11 Feb 2007 Posts: 806 Location: derbyshire
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Posted: Fri Jul 06, 18 12:27 pm Post subject: |
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Thanks for that, yes that's definitely it, interesting article and quite long living creature. |
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Mistress Rose
Joined: 21 Jul 2011 Posts: 10312
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Posted: Sat Jul 07, 18 6:54 am Post subject: |
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I have always known them as sea urchin shells, but never seen a live one that could be identified as being from one. I have a little one I picked up on a beach in Devon. |
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sean Downsizer Moderator
Joined: 28 Oct 2004 Posts: 41939 Location: North Devon
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dpack
Joined: 02 Jul 2005 Posts: 34738 Location: yes
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Posted: Sat Aug 18, 18 10:20 pm Post subject: |
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iirc they live n die as a collective so i spose if any wash up it is often many in one go.
if it has been calm for a while any dead ones will get stirred up at the same time.
ages ago i saw a bunch of freshish ( not very fresh ) ones that still had some spines and contents after a storm and tide had swirled em out of the sand onto the beach.
as soon as you go below lowest low tide there are a huge variety of odd beasties, sea squirts have ace comedy value if one's chums have never been handed one before, especially when the single cavity two holes thing is explained,
there is a high probability that our gt gt ( to the power N where N is a very big number ) grannie was a sea squirt of some sort.
iirc tunicates are first in the fossil record for anything resembling a gut with two ends |
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Hairyloon
Joined: 20 Nov 2008 Posts: 15151 Location: Today I are mostly being in Yorkshire.
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Posted: Sun Aug 19, 18 8:54 am Post subject: |
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dpack wrote: |
there is a high probability that our gt gt ( to the power N where N is a very big number ) grannie was a sea squirt of some sort.
iirc tunicates are first in the fossil record for anything resembling a gut with two ends |
I think the more relevant feature is the beginnings of a backbone. |
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dpack
Joined: 02 Jul 2005 Posts: 34738 Location: yes
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Posted: Sun Aug 19, 18 11:12 am Post subject: |
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the gut evolved long before chordata.
tunicates predate worms, molluscs etc etc and seem to be a direct ancestor of all tubes. |
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