Mystery Beach find: To fresh to be rudist. Solved:barnacle

[Mahnmut]

Ahoi dear forum members.

While reading  a little bit about rudists some of the structures in picture of a broken Hippurites and the shape of Lapeirusia crateriformis reminded me remotely of a still unidentified beachfind from my last big holiday.

That doesn´t say much, as apparently rudist could look like anything they wanted, but still I wonder what the fragment I found may be. Found it in the pacific driftline, broken like you see it.

There are some barnacles, some serpulids, maybe a little bivalve also, but I wonder what the enclosing structure is.

Any ideas?

Aloha,

J

[Al Dente]

It’s a barnacle.

[Mahnmut]

Thanks Al,

I wouldn´t have thought that. It is quite different from all the barnacles I have seen before.

Can you tell me something more about it?

Best Regards,

J

[Mahnmut]

OK, I learned something:

most barnacles I knew before do show relatively separate segments, like the one segment in the midle of the picture below (coronula diadema, one of my most special fossils),

but there are others that look much more compact like my former mystery. A quick image search tells me that for example the family Tetraclitidae can be like that.

Thanks again!

 

Edited February 19, 2020 by Mahnmut
clarification