1. Superfamily Globigerinacea
Lecture 11
Superfamily Globigerinacea

2. Superfamily Globigerinacea
The planktonic Globigerinacea typically have trochospirally coiled shells with inflated, coarsely perforate chambers being fine spines during life (e.g. Hastigerinella).
The wall of the Globigerinacea is composed of optically radial and bilamellar, low magnesian calcite.
Although the primary aperture is usually basal, aerial or terminal.
Secondary sutural or aerial apertures are also found.
These apertures may be partially covered by one or several flaps called bullae.
Although inflated chambers are characteristic, some genera have club-shaped (Clavate) chambers (Hastigerinoides), while others, including the Rotaliporidae, Globotruncanidae and Globorotaliidae have keeled outer margins (Globotruncana; Upper Cretaceous and Globorotalia, Paleocene – Recent).

4. Ornament is not prominent but the tests often have a rugose or pustulose surface, and rarely longitudinal coastae.
Forms which are not trochospiral include the ancestral Heteohelicidae (High trochospiral- biserial-uniserial, (Heterohelix, Upper Cretaceous and the planispiral Hantkeninidae (Hastigerinoides).
Widely used for correlation are species of Globotruncana, Globorotalia, Globigerina and Orbulina.
The final, spherical orbuline, chamber of Orbulina completely envelopes the earlier, globigerine coil.

5. a.Heterohelix d.Globorotalia e. Globigerina f. Orbulina
b.Hastigerinoides
c.Globotruncana
d.Globorotalia
e. Globigerina
f. Orbulina

6. Heterohelix
Globotruncana arca
Orbulina universa
Globorotalia tosaensis Takayanagi and Saito
Globigerinoides ruber

7. Globigerinita glutinata
Sphaeroidinellopsis subdehiscens (Blow)
Globigerinita dissimilis (Cushman and Bermudez(

8. Superfamily Rotaliacea
Tests of rotaliaceans are built of optically radial bilamelar calcite.
They are distinguished by the presence of rotaliid septal flaps and canals.
In the commonly brackish-water genus Ammonia the umbilicus is partly filled by small calcite pillars.
Elphidium is another common genus, with an involute planispiral test. A sutural canal system opens at the surface through sutural pores, the latter defined by backward projecting rods called retral processes.
Calcarina is a tropical genus in which the trochospiral test bears robust spines from a thick outer wall.
Nummulites are rotaliacean larger foraminifera widely used in correlating Eocene rocks from around the old-world Tethys Ocean but their descendants are still found today in the Indo-Pacific seas.
Their tests are radial hyaline and perforate with rotaliid septa.
Coiling is biconvex planispiral.
Involute forms reveal V-shaped cavities in axial sections.

9. Ammonia
Elphidium
Calcarina

10. Detail of axial section,Nummulites test and detail of spiral section
Five main types of septal filament
on Nummulites tests
Spiroclypeus
Nummulites obesus

11. Superfamily Cassidulinacea
The Cassidulinacea comprise small benthic foraminifera with optically granular, cryptolamellar calcite walls and slit-tear-or-loop-shaped apertures, generally areal or terminal.
In Cassidulina the test is lenticular, consisting of biserially arranged chambers coiled in a plane spiral.
Straight biserial followed by uniserial growth is seen in Loxostomum.
Virgulinella with supplementary sutural apertures.
Pleurostomella is uniserial throughout, with a terminal aperture and two "teeth".

12. Cassidulina reniforme Nørvang
Cassidulina carinata

13. Pleurostomella
Loxostomum
Virgulinella
Cassidulina

14. Superfamily Nonionacea
The wall structure of nonionacean tests is of optically granular, crypto-lamellar or bilamellar calcite.
The aperture is generally a basal slit.
Two involute planispiral tests of the genera Nonion and Melonis differ largerly in the degree of chamber inflataion.
In Osangularia, the test is trochospiral with a keel and a closed umbilicus.

15. Osangularia-bengalensis
Nonion depresselum
Meloni pompilioides
Osangularia-bengalensis

16. Nonion
Melonis
Osangularia

17. Superfamily Carterinaea
It represented by the single genus Carterina.
In this unusual foraminiferid the wall is composed of monocrystalline calcite spicules arranged parallel within a calcite matrix.
The tests are distinguished after death and are not known as fossils.
The aperture of Carterina is large and umbilical in position and the chambers are divided into chamberlets by septulae.
It seems that is most closely related to the discorbaceans.