ForaminiferaMarcelle BouDagher-Fadel

HOW TO RECOGNIZE A PLANKTONIC FORAMINIFERA

By its simplicity

Lacks the additional skeletalStructures characteristics ofBenthic foraminifera

No plugsNo pillarsNo canal system

No internal structure, or tooth-plates in thin sections or solid, lips sticking out or in from the simple aperture

Aperture simpleAlthough the aperture may be modified exteriorly by apertural lips, portici, tegillum….)

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

Wall texture of planktonic foraminifera

Spinose

cancellateGlobigernoides

smooth

Cancellate - spinose

muricatePulleniatina

Hastigerina

Morozovella

Appearance of first planktonic foraminifera

keel elongate chamber

extensions

biserialMuricae fusing

Large perforationswide umbilicus

GlobigerinoidesGloborotalia

spineskeelDorsal view

Peripheral view

Umbilical view Dorsal apertures

Umbilical viewaperture

• 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

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.