Image C3 might be lateral cut of Choffatella sp. or any relevant spceies in its subfamily too.

This paper might help:

Lower Aptian shallow-water benthic foraminiferal assemblage from the

Chilacachapa range in the Guerrero-Morelos Platform, south Mexico

By Lourdes Omaña* and Gloria Alencáster

Departamento de Paleontología, Instituto de Geología, Universidad Nacional Autónoma de México,

Ciudad Universitaria, 04510, México, D. F., México.

* [email protected]

Lower Aptian benthic foraminiferal assemblage from the Chilacachapa range 575

ABSTRACT

Lower Cretaceous shallow-water benthic foraminifera were recovered from the lower part of a limestone sequence that crops out in the Chilacachapa range in the Guerrero-Morelos Platform paleogeographic unit in southern Mexico. The benthic foraminiferal association consists of Palorbitolina lenticularis, Choffatella cf. decipiens, Melathrokerion valserinensis, Glomospira urgoniana, Istriloculina eliptica, Pseudocyclammina sp., Ammovertellina sp., and Lenticulina sp. This association is documented here for the first time in the study area and Melathrokerion valserinensis for the first time in Mexico. An early Aptian age was assigned to the sequence on the basis of the size of the embryonic chamber and test characters of Palorbitolina lenticularis.

The observed lithology and foraminiferal faunas suggest a warm shallow-water platform environment. The benthic foraminiferal ssemblage is considered typical of the Tethys realm, corresponding

to the Barremian-Aptian boundary platform expansion, as the same benthic foraminifera are present at many localities in the Old and New World.

Key words: benthic foraminifera, shallow-water platform, Tethys realm, early Aptian, Chilacachapa

range, Guerrero-Morelos platform, Mexico.

Dear Dr Shulka

Thanks a lot, Image C1 is Similar to Image f in the article you introduced.

And based on that article is the oblique cut of Choffatella too.

If Images C1 and C3 are Choffatella decipiens Schlumberger Em. Maync, 1950 now accepted as Choffatella cruciensis (Pictet & Renevier, 1854) , which is hard to say due to the oblique cuts , then the age of this section would be Hauterivian to Aptian in the

Tethys basin. According to Granier et al (2003) in stratigraphy study of offshore Abu Dhabi" Foraminifer Choffatella decipiens in Hauterivian and possibly Early Barremian times inhabited shallow water environments in association with calcareous green algae, but in the Late Barremian and thereafter is found only in deeper environments. This change in habitat may be related to the presence of new competitors, i.e. representatives of the orbitolinids, and the change may be useful in discriminating the two Barremian sub-stages"

Since no green algae present in my sections one can infer it does probably not belong to shallow environment so according to the mentioned article the age would be Late Barremian to Aptian, but in order to certify that I would be thankful if anyone can determine which species of the genus Pseudocyclammina is image C2?

фото сверху - это Rectocyclammina arrabidensis Remalho (кимеридж-берриас)

Фото слева снизу - Аlveosepta powersi (Redmond) (кимеридж)

справа снизу - Аlveosepta powersi (возможно)