- according to Hottinger (2006):
Remarks: This term, introduced for Ammonia by Cifelli (1962), was substituted erroneously by Parvati (1971) by "umbilical plate" but in fact is a cover plate. Continued use of the term "axial plate" would add to the considerable confusion in the current concepts of rotaliid umbilical architecture (see also Lévy et alii, 1986).
Cifelli (1962), Morphology and structure of Ammonia beccarii (LINNÉ), Contributions from the Cushman Foundation for Foraminiferal Research, New York, vol. 13, p. 119-126.
Hottinger (2006), Illustrated glossary of terms used in foraminiferal research. Carnets de Géologie, Memoir 2, ISSN 1634-0744
Lévy, Mathieu, Poignant & Rosset-Moulinier (1986), Discorbidae and Rotaliidae: a classification to be revised.- Journal of foraminiferal Research, Lawrence, vol. 16, N° 1, p. 63–70.
Parvati (1971), A study of some rotaliid Foraminifera I, Koninklijke Nederlandse Akademie van Wetenschappen, Proceedings, Amsterdam, (series B), vol. 74, p. 1-26.