Simona:

Resemblance to a species of Ammobaculites is superficial and concerns only similar agglutinating grains, warranting further analysis as per the link provided:

 https://www.researchgate.net/publication/240779339_Mineralogy_of_agglutinated_benthic_foraminifera_implications_for_paleo-environmental_reconstructions

Best

Syed

Article Mineralogy of agglutinated benthic foraminifera; implication...

Dear Simona I think it genus Haplophragmoides not Ammobaculites 

Dear Simona,

for genus assignment, the location of the aperture appears crucial in this case. Unfortunately, I can not find the aperture on the figures. If the aperture is located at or near the base of the last chamber I would refer the specimen to Haplophragmoides. For Ammobaculites, the aperture should be located right in the middle of the terminal face. Do you have any specimens where you can see the aperture?

Cheers from Hamburg,

Gerhard

Dear Simona

I guess it seemingly Haplophragmoides. So I agree with Letizia and the notes of Gerhard is also god and must put in consideration and i think that from photos 2,3 the aperture is at base of the last chamber and somewhat obscured.  Your photos is most probably Haplophragmoides

Simona:

Have a look at this link for the original description and lectotype designation of Ammobaculites:

 http://nhm2.uio.no/norges/atlas/070_txt.htm

Assignment to Haplophragmoides sp. can be made.

Best

Syed

First time I saw this species I thought that it might belong to the genera Haplophragmoides. When I got the SEM I saw that the grains size is coarse silt whereas Haplophragmoides shells are composed of fine silt grains (EDWARDS&WRIGHT, 2015). Today I went through the refs that had been advised along this chain of answers and other classification books and papers and after collecting and re-inspecting the diagnostic criteria of several specimens I have more confident that this species belongs to the genera Ammobaculites. In the same samples that these specimens are found I have at least two more species of Ammobaculites- attached. It seems that the specimens that I attached to my question are the initial planispiral forms (4-5 chambers observed in the final whorl and depressed umbilicus). If you will look carefully on the third image I send couple of days ago, you'll see (though not so clearly!) a round terminal aperture (maybe partly broken) in the middle of the terminal face- the last chamber where it is a bit pointed. Anyhow, I'll do some more SEM with better specimens that are showing better these indicative features.

I really appreciate all of you for your answers and input.

Many thanks and best regards from sunny LA (°32 C/°88F today!!)  

Simona            

Hi Simona,

Doesn't look like a Haplo to me. I think you have two different things though. The first images look a bit like what I had in southern England and called Ammoscalaria runiana although the test was typically so coarse-grained that you could not make out the chambers so well (but that was under an optical microscope). I think the little pit on the terminal face is damage - the terminal aperture on Ammobaculties is pretty distinct. esp. under SEM. The second set of images in which you have uniserial latter chambers does look like Ammobaculites of some sort. We figured quite a few variants in Wright et al. 2011 (link below) but I don't pretend to be a taxonomist (!) and we lumped them since they weren't especially diagnostic for sea level stuff.

Not sure if that helps or just makes things more confusing!

Cheers,

Robin

Article Reassessing transfer-function performance in sea-level recon...

Simona:

From the beginning your question and the pictures were confusing. The second set of pictures do reveal features of Ammobaculites without specific assignment. Coarse silt on the test of Ammobaculites and fine silt on the tests of Haplo. is misleading - see tests of H. volgensis. In some salt-marsh settings species of both Ammobaculites and Haplo. are common (see link: http://arxiv.org/pdf/1508.02010.pdf). You need to freshly document and assess your material.

Best

Syed

Dealing with taxonomy is occasionally not as straightforward as one might think (!) as this case demonstrates- but you know that already. I am assessing the taxonomic identifications based on all diagnostic criteria, not merely on test granulometry, of course.

Anyhow.. I'm going to do some more SEMs that show better the aperture and other significant characteristics. I am sorting as much as possible into species level, nonetheless I'm going to lump all Ammobaculites genus- into a single group following your work, Robin, and others (e.g. Kemp et al., 2009; Milker et al., 2015) because they were occasionally broken making it difficult to assign them to species level and also because they are not key species for sea level studies.

I must say that I find the communication via this platform very meaningful and enlightening…thank you guys.