Dear Vincenzo,

P. tunesiana should be the only upper Aptian species of the genus, and maybe your identification is correct; but you need other sections with different orientation to be sure of that. Conicals agglutinated are however quite difficult to identify in random sections, here you have at least two morphotypes, or maybe three. The other morphotype you have identified as Dictyoconus remembers me the genus Cribellopsis; try to get more sections.

All the best

LC

Thank you very much Lorenzo, I'll take you advice! If you have any references to suggest, it would be much appreciated.

Hi Dear Vincenzo

All of your specimens are Dictyoconus and have changed shape in the course of limestone fossilization. In my opinion, there is no doubt about this.

best Regards

📷

Dear Dr. Randazzo,

First of all, I exclude the presence of Urgonina due to its simple endoskeleton, and the internal characteristics of Dictyocouns are quite away from your figures..

In the genus Paracoskinolina, the chambers are undivided with the presence of pillars and two orders beams.

While the genus Cribellopsis has no pillars, one type of beams and the chambers are subdivided into chamberlets.

Therefore, your figures are quite similar to cf. Cribellopsis aff. arnaudae and is compatible with the age you suggest

.See,

- Abad, Erzika Cruz, 2018, TEXTURA Y ARQUITECTURA DE LOS ORBITOLINOIDEOS (SUPERFAMILIA ORBITOLINOIDEA): REVISIÓN Y CARACTERIZACIÓN.Ph.D. Thesis, University of Barcelona.

- Mancinelli, Anna & ChiocchiniMaurizio, 2006, Cretaceous benthic foraminifers and calcareous algae from Monte Cairo (southern Latium, Italy).

Bollettino della Società Paleontologica Italiana, 45 (1), 2006, 91-113. Modena, 30 settembre 2006

Wish you the best

Mamoun

Thanks for your exhaustive answer Mamoun! I've already read the paper from Chiocchini and Mancinelli 2006, Mt. Cairo assemblage seems well comparable with mine. That is why I thought of Paracoskinolina tunesiana. I'll read that PhD thesis accurately, it seems very interesting and I'm confident it will clarify my doubts.

Regards,

Vincenzo

Hi Vicenzo,

just three remarks from my side:

1. Urgonina = subaxial section of Orbitolinopsis kiliani Silvestri

2. Paracoskinolina cf. reicheli = transverse section f an orbitolinid with pillars and one intercalary beam (right side)..such type of sections can be found among various taxa (e.g. P. reicheli, P. sunnilandensis, D. walnutensis etc.)...without axial sections that show the arrangement of the pillars (aligned or alternating) and the presence/absence of rafters in the marginal zone, generic and specific determination is almost impossible.

3. The presence of Orbitolinopsis kiliani challenges your upper Aptian age.

Hope this helps a little bit...more thin-sections = more specimens = more and better determinations = more and better stratigraphy : - )))

Saluti

Felix

Post script....and in M11 and M13 the structural elements of the central zone are not aligned excluding a belonging to Paracoskinolina Moullade.

Thanks Felix! I'll take your advice and make more thin-sections, but you already helped me a lot. I really would like to learn how to identify these nice little beasts

:-) suggestions about references will be super appreciated. Grazie mille!

Saluti,

Vincenzo

Thanks Vincenzo...Unfortunately nothing replaces decades of experience.. :-))))...but as a good starting point I recommend Arnaud-Vanneau 1980...the chapter on Orbitolinidae...a very helpful generic determination table...it is in French but worth to read the chapter in each detail. It is also available online.

I can only imagine :-) ...thanks again!

Hi again Cretaceous experts!

I have some important updates concerning this question. Thanks to Felix Schlagintweit's precious help, I managed to solve my orbitolinid problems and together we carried out a nice paper just published on Cretaceous Research. You'll find a couple of tables full of orbitolinids and other amazing beasts, give them a look!

Here you can freely download it https://authors.elsevier.com/a/1dDty_4Skwx9L6

Cheers,

Vincenzo