This document provides information about identifying and recognizing planktonic foraminifera. It notes that planktonic foraminifera lack additional skeletal structures found in benthic foraminifera, have a simple aperture, can permanently float or drift in the water column, and are very abundant in inner to outer neritic sediments. It also describes the wall textures of different planktonic foraminifera species and how their morphology has evolved over time, including developing elongate chamber extensions, becoming biserial, and muricae fusing.

1. Foraminifera
Marcelle BouDagher-Fadel

2. HOW TO RECOGNIZE A
PLANKTONIC FORAMINIFERA
By its simplicity
Lacks the additional skeletal
Structures characteristics of
Benthic foraminifera
No plugs
No pillars
No canal
system
No internal structure, or tooth-plates in thin
sections or solid, lips sticking out or in
from the simple aperture
Aperturesimple
Although the aperture may be
modified exteriorly by apertural
lips, portici, tegillum….)

3. Planktic (planktonic) foraminifera can
permanently float or drift in the water
column.
They are widespread and have had
rapidly evolving lineages
They are very abundant in inner to
outer neritic sediments

4. Wall texture of planktonic foraminifera
Spinose
cancellate
Globigernoides
smooth
Cancellate - spinose
muricatePulleniatina
Hastigerina
Morozovella

6. Appearance of first
planktonic foraminifera

10. keel elongate chamber
extensions
biserial
Muricae fusing
Large perforationswide umbilicus

17. Globigerinoides
Globorotalia
spineskeel
Dorsal view
Peripheral view
Umbilical view Dorsal apertures
Umbilical view
aperture

19. • Planktic/Benthic
• Paleodepth: planktic forams not in coastal
zones (neritic), P/B >>100 in open ocean
• Dissolution: planktic forams fragment,
dissolve before benthics; deep-sea floor low
P/B values indicate depth below lysocline
• Surface productivity: more difficult, but at
higher food supply productivity (or: in
shallower waters) more benthic foraminifera

22. BouDagher-Fadel, M.K., Banner, F.T. and Whittaker, J.E., 1997. Early Evolutionary
History of Planktonic Foraminifera, British Micropalaeontological Society
Publication Series, Chapman and Hall Publishers, pp 269.
Haynes, J.R., 1981. Foraminifera. MacMillan, London, pp 433.