Is it a sponge ?

[fifbrindacier]

Hi everybody, that's not the first time i consult that very interesting site, specially to try to identify the sponges i have.
I suppose the following piece is a sponge.
I found it in the Cenomanian of the village or Port des Barques near the town of Rochefort, in the department of Charentes-Maritimes, Sputh-West of France.
The scale i used is in centimeters.

[hubertus68]

Hi! Welcome to to fossiel.net. It is indeed a very interesting site and a perfect place for discussion.

Could you post some close-up pictures of your fossil? This would help a lot for determination.

Best wishes,
Oliver

[fifbrindacier]

Thank you Oliver, i have magnified the photos i have. I'll take more tomorrow if necessary.

[hubertus68]

Yes, additional photos are indeed neccessary. The ones you magnified are unfortunately too bad for determination.

Best wishes,
Oliver

[FossilDude]

Have you considered the possibility that it could be a coral? Maybe something in the family of Helioporidae, like Polytremacis?

Cheers,
Johan

[Bewerkt door FossilDude op 11-10-2017 om 22:15 NL]

[fifbrindacier]

Hi, fossildude. I had concidered it could be some kind of coral, but i'm knew in the fossil domain, and the idea it could be a sponge rather than a coral predominated. I agree that your proposition is a good one.
And i also find that you have a really nice nautilus.

[FossilDude]

Thank you for the compliment.

Maybe you can try to take a close-up photograph of some of the better preserved parts of the specimen, as Oliver already suggested. In the attached photograph I've indicated a part that would be suitable for this.

If it's a Helioporid coral, we should be able to discern the apertures of the smaller zooids. These are tiny little holes surrounding the larger ones.

Cheers,
Johan

[fifbrindacier]

Hi, as promised i took some pics of the zone you showed me.

[hubertus68]

Dear ?

thank you for the additional pictures. To me it is still not identifyable. I don't see any septae that would hint to a coral. The surface shows no regular structure and is possibly eroded. This makes is difficult to state if this is a coral or f.e. a bryozoan colony. Here is an example of the bryozoon Celleporaria palmata from miocene deposits of France, that lives in symbiosis with the coral Cryptangia: https://www.fossiel.net/id_system/fossi ... =5040-0006

Finally only a view on transverse or longitudinal sections can lead to a solution.

Best wishes,
Oliver



[Bewerkt door hubertus68 op 12-10-2017 om 11:32 NL]

[fifbrindacier]

Thank you very much for your answers, both of you.
Cheers.
Sophie.