Original Description Test with chambers added alternately with respect to the test groth axis resulting in a biserial arrangement. Earlier chambers are globular, those of the adult stage petaloid, subrectangular or with antero-posterior elongation. Sutures are distinct and depressed, often hardly visible between earlier chambers of the test. Test compressed in edge view; periphery is simple, without peripheral structures. Aperture is a subcircular to subogival arch at the base of the last formed chamber. Chamber ornamentation consists of leptocostae; well-developed periapertural pustulose area. Test wall calcitic, hyaline and perforate. Size: Etymology: name derived from the Latin prefix plano- (= plane) to which the suffix -itella is added; the reference is to the compressed tests in lateral view.
Extra details from original publication Remarks.– Planulitella differs from Protoheterohelix Georgescu and Huber, 2009 (late Albian-early Turonian) mainly by having symmetrical tests and periapertural structures. It differs from Planoheterohelix (middle Cenomanian-lower Maastrichtian) by having compressed tests in edge view, larger pores (1.1-4.4 μm rather than 0.5-0.9 μm) and chambers ornamented with thicker leptocostae, which can be coarser over the earlier portion of the test. Heterohelix Ehrenberg, 1843 (early Turonian-Santonian) also presents slightly compressed tests but differs from Planulitella by having lateral tubulospine-like projections, smooth or finely striate tests and finer pores (0.4-0.8 μm rather than 1.1-4.4 μm).
Planulitella sphenoides (Masters, 1976),
P. stenopos (Masters, 1976)
P. malocaucasica (Aliyulla in Geodakchan & Aliyulla, 1959).
Stratigraphic range.– Santonian (from the uppermost part of D. concavata Biozone to D. asymetrica Biozone). Editors' Notes
Georgescu, M. D. (2010d). Origin, taxonomic revision and evolutionary classification of the late Coniacian-early Campanian (Late Cretaceous) planktic foraminifera with multichamber growth in the adult stage. Revista Española de Micropaleontología. 42: 59-118. gsVO
Planulitella compiled by the pforams@mikrotax project teamviewed: 2-2-2023