oyo

As I have already said it is impossible to differentiate these genres with the naked eye. Thin sections are required. As can be seen in the articles I cite, the differences between these genres are the presence or absence of penular structures, trabeculae and their density, septal perforations and their regularity or absence, presence of synapticules and quantity of them, etc. Elements all of them that can only be observed in this type of preparations. In fact Mr. Lathuiliere includes some more genre in this matter, Periseris for example. In most cases even polished sections would not be sufficiently definitive to assert membership in one genre or another. There are times that is possible affirm with the naked eye the genre of the materials but it is not the case of these materials that you have posted. It are materials that at first sight are quite similar.

Difficult to identify. Thamnasteriod coral, very common design. It´s necessary to see thin sections. At least polished sections. As you said, it may be Thamnasteria. Or as he told you, Dimorpharaea. Stephanastrea with thamnasteroid appearance, even. I recommend to you Lathuiliere B. 2000 Coraux constructeurs du Bajocien Inf. de France Part1 et 2. Geobios. If you don´t have it I can send it by mail. I don´t have links. With that documentation and the specific location, Nievre is too broad, perhaps you can adjust it.

Pudiese ser peor. https://www.google.es/url?sa=t&rct=j&q=&esrc=s&source=web&cd=16&cad=rja&uact=8&ved=0ahUKEwj1teue_8_VAhWqAsAKHfPkDEA4ChAWCDIwBQ&url=http%3A%2F%2Fashipunov.info%2Fshipunov%2Fschool%2Fbooks%2Fdubatolov1971_devonsk_korall_dzhungar_balkhashsk_prov_igig_074.pdf&usg=AFQjCNHlRyj_R_LwL5cfAVKLospZOy4iCw https://www.google.es/url?sa=t&rct=j&q=&esrc=s&source=web&cd=17&cad=rja&uact=8&ved=0ahUKEwj1teue_8_VAhWqAsAKHfPkDEA4ChAWCDQwBg&url=http%3A%2F%2Fashipunov.info%2Fshipunov%2Fschool%2Fbooks%2Fivanovskij1976_ukaz_rodov_rugoz_igig_217.pdf&usg=AFQjCNF0xbanKZFzZzCoLF1ofGK9DJNWJw

https://www.google.es/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwj1nJGz7M_VAhVCDMAKHbuFC0oQFggmMAA&url=http%3A%2F%2Fcdn.palass.org%2Fpublications%2Fpalaeontology%2Fvolume_12%2Fpdf%2Fvol12_part2_pp178-188.pdf&usg=AFQjCNH_KhPIwsbxlEodISNi7AIQid_qVA https://www.google.es/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0ahUKEwjF8pK57c_VAhXLIMAKHRMqCHwQFggyMAI&url=https%3A%2F%2Fwww.app.pan.pl%2Farchive%2Fpublished%2Fapp25%2Fapp25-633.pdf&usg=AFQjCNEJdGNBtk2F8HlyUxZc-wOmQIHrpg

This happens by talking with a single image in the head. An image of walls with pores and without visible septum. Like this. Then one looks at it more calmly and notices the error. It is recognized, the reason is given to who has it and solved it. It's not complicated. Maybe it's rare but not for me.

Yes, you are right. I was wrong.

Mmmmmmm. It aren't corals, for me. Calcareous algae or calcareous sponges.

Oui, fosil. Crinoideo-lys de mer.

De rien, para uso y disfrute de los interesados, en general.

Por si usted, o cualquiera, quiere profundizar en el tema de los Demospongiae, una revisión moderna. Con distribuciones geográficas y estratigráficas. https://www.researchgate.net/publication/257559077_Hypercalcified_Extant_and_Fossil_Chaetetid-Type_and_Post-Devonian_Stromatoporoid-Type_Demospongiae_Systematic_Descriptions

Para que los compare con sus ejemplares. Luteciense surpirenaico.

La edad de ese que he puesto ni idea. Lo he sacado de una pagina rusa y no pone edad. Yo los tengo terciarios, lutecienses más concretamente. Los hay Mesozoicos y Cenozoicos, creo que también Primarios. Malos fósiles-guía. La edad de este del post nos la debería decir la recolectora de los ejemplares. Bonjour Chantal. Those photographs are much clearer. Next50 caught it at first. Nº2 Chaetetes for me. It are sponges.

For nº 2.

Y para Warrior45, muy bonitos ejemplares, e interesantes. Los números 4 y 6 son Dimorphocoeniopsis beauvaisorum (Zlatarski 1967), interesantes ejemplares. El resto tengo que buscarlos, alguno más seguro que puedo identificar. Saludos