single-celled organisms (protists) Such organisms are classified in the Superkingdom of Protists or Protista

1. Foraminifera
Marcelle BouDagher-Fadel

2. What are Foraminifera:
• with characteristic net-like pseudopodia called
reticulopodia
• organic or shell-like, agglutinated or secreted
outer protective layer, called a test
single-celled organisms (protists) Such
organisms are classified in the Superkingdom
of Protists or Protista
with a complex cell (Eukaryotes), and genetic
material within a cell nucleus.
Cytoplasm is extruded as pseudopods
through the aperture and any perforations
in the test

3. Foraminifera are placed in the “Cercozoa”.
Cercozoans are amoebae with filose pseudopodia, often living within hard test

4. Most foraminifera grow an elaborate, solid
calcite skeleton
made of a series of chambers.
The complexity of their shell structures
and their evolution in time
the basis of their geological usefulness
as fossils.
Most foraminiferal tests are sand-sized
(>61 mm in diameter)

5. Both living and fossil foraminifera
• inhabited the oceans.
• They are extremely abundant in
most marine sediments
• in many different environments,
from live in marine to brackish
habitats
• near shore to the deep sea,
• and from near surface to the
ocean floor
• Some foraminifera
live in oligotrophic
reef associated with
algae.

6. Composition of fossil foraminifera tests varies from
• calcareous secreted from
calcium carbonate.
• agglutinated (organic
compounds, sand grains and
other particles cemented
together, or crystalline calcite)

7. The test is commonly divided into chambers which are added
during growth
The size of the test is associated with amount of the cytoplasm.
Feeding adds to the bulk of the cytoplasm, therefore, the test has to enlarge.
Foraminifera have developed several strategies for test enlargement during ontogeny
contained growth unilocular test
The test is thought to reduce biological, physical and chemical stress
continuous growth Bilocular test
simple septate growth
multilocular
complex septate
growth
Complex multiocular test
These growth patterns result in a very diverse variety of test morphologies

8. the simplest forms are open tubes
or hollow spheres
Both living and fossil foraminifera come in a variety of shapes and sizes
Spirillina
Planispiral, evolute, undivided tube
Lagena
Undivided chamber
reticulation

9. a: aperture; ad: adapertural depression; li:
lip; tp: toothplate with its serrated margin.
Loxostomina.
A-B: Globoturborotalites
Carpenteria
cancellation
perture terminal
Secondary aperture Main aperture
aperture

10. Planipiral involute
Elphidium
Planipiral evolute
Spirillina
milioline
Quinqueloculina
biserial
Heterohelix
streptospiral
Pulleniatina
trochospiral
Ammonia

11. Streptospiral
Planispiral Trochospiral

12. What are fossil foraminifera?
Fossils can be microscopic
or
a few centimeters long
They have inhabited the oceans for more than 500 million years and found
fossilised in most type of sedimentary rocks.
Most foraminifers construct tests (shells) covering the cell body.
Fossil foraminifera are the remains of their tests (shells).
Fully grown individuals range in size from
about 100 micrometers to almost 20
centimeters long.

13. because there can be thousands of specimens in a small sediment sample.
relatively small size of tests
(shells)
makes foraminifera
For,
biostratigraphic,
palaeo/environmental, palaeoceanographical
and palaeoclimatological reconstruction
or petroleum exploration applications
much more useful
than larger fossils

15. The study of the sequence of sedimentary rock strata is the main source for scientific
knowledge about the Earth’s history, including biostratigraphy, paleogeography,
paleoclimatology and the history of life

18. • Orders of foraminifera (underlined include larger foraminifera (see BouDagher-Fadel, 2008). In
red includes planktonic foraminifera)
• ALLOGROMIDA: organic wall, usually 1 chamber; Cambrian-Recent
• ASTRORHIZIDA: agglutinated, organic cement, usually 1 chamber or branching tube; Cambrian-
Recent
• LITUOLIDA: agglutinated, organic cement, many chambers, usually planispiral spiral; Cambrian-
Recent
• TROCHAMMINIDA: agglutinated; organic cement, many chambers, usually trochospiral; Cambrian-
TEXTULARIIDA: agglutinated, low Mg-calcite cement; Cambrian-Recent
• FUSULINIDA: microgranular calcite; many complex chambers; Silurian-Permian
• MILIOLIDA: high Mg calcite, imperforate, many chambers (porcellaneous, no pores); miliolid
chamber arrangment; Carboniferous-Recent
• CARTERINIDA: low Mg calcite, hyaline, pores or no pores; spicules, plani- or trochospiral; Tertiary-
Recent (?)
• SPIRILLINIDA: low Mg calcite; hyaline; single crystal; spiral; Jurassic-Recent
• LAGENIDA: low Mg calcite, hyaline; pores, 1 or many chambers, uniserial or planispiral;
monolamellar; Carboniferous-Recent
• BULIMINIDA: low Mg calcite; hyaline; pores; many chambers; bilamellar; toothplate; Triassic?-
Recent
• ROTALIIDA: low Mg calcite; hyaline; pores; many chambers; bilamellar; trocho- or planispiral,
annular, irregular; Triassic-Recent
• GLOBIGERINIDA: low Mg calcite (aragonite in few extinct forms); pores; many chambers; bilamellar;
radial crystals (PLANKTON); Jurassic-Recent
• INVOLUTINIDA: aragonite; 2 chambers - 2nd tube
• ROBERTINIDA: aragonite; pores; many chambers; trochospiral; Triassic-Recent
• SILICOLOCULINIDA:opaline silica, no pores; chamber arrangements as in miliolids; Miocene-
Recent
• Genetic evidence suggests strongly that Allogromida (‘naked’) and Astrorhizida (agglutinated) are
one order.

19. Life strategy
Float in the surface of the open ocean
and sea water column
Wide distribution
Rapid evolution + short stratigraphic range
= excellent index fossil
Benthic foraminifera
Live attached or free
At all depth
marine, brackish and freshwater habitats
sea-floor
Small
Larger
Planktonic foraminifera

20. • Benthic foraminifera are bottom dwelling forms
that can be either sessile or vagile.
Benthic foraminifera
•Vagile (mobile) foraminifera
are free to move along the sea
floor and/or in its substrate
Cassidulina
•Sessile foraminifera are
permanently attached or fixed
(not free-moving)
Ammobacculites
Miniacina

21. Benthic foraminifera
Small benthic foraminifera Larger benthic foraminifera
include two major groups of foraminifera
occur abundantly in the shelf regions of
most tropical and subtropical shallow
marine, especially in carbonate-rich,
environments
live, attached or free, at all
depths, in most marine
environments, as well as in
brackish, marginal marine
environment with low alkanity.
with complicated internal structureswith simple internal structures

22. •Benthic foraminifera are an important component of the deep-sea
biomass in the present oceans, adapted to its cold, dark, and extremely
oligotrophic environments.
•Larger benthic foraminifera are important shallow marine rock builders
• Faunas are highly diverse,
and many species have a
cosmopolitan distribution.
•In addition to their interest as
indicator species living in the largest
habitat on earth, their tests have been
used extensively in isotope and trace
element analysis aimed at
reconstruction of past environments.

25. Larger Foraminifera with test sizes from 2mm up to 13cm are characteristic
organisms inhabiting shallow water subtropical and tropical environments
today.

26. Alveolina

30. Two main factors acting as single
gradients regulate the distribution of
larger foraminifera within coral reef
complexes.
Larger foraminifera prefer clear, nutrition
depleted water as can be found in the
surroundings of coral reefs.
All house symbiotic microalgae and are
thus restricted to the photic zone (-130m),
getting independence from food resources
outside the cell.
House symbiotic algae

32. Allogromia has a
proteinaceous test
with a single
chamber.
The oldest fossil foraminifera, from the
Cambrian, are simple agglutinated tubes.

35. Bulimina
Cibicidoides

37. Fusulina
rice-grain shaped tests and evolved into numerous
widespread species during the Permian but large forms
went extinct at the end of that period when a worldwide
mass extinction also eliminated most other reef dwelling
organisms.

42. BouDagher-Fadel, M.K., 2008.
Evolution and Geological Significance of Larger Benthic Foraminifera
, Developments in Palaeontology and
Stratigraphy, 21, Elsevier, Amsterdam, pp 544.
Haynes, J.R., 1981. Foraminifera.
MacMillan, London, pp 433.