Foraminifer

The species of foraminifer which composes, almost to the exclusion of all others, the deep Atlantic mud, is called Globigerina. […] The natural home of the foraminifers appears to be in the deeper parts of the ocean, commencing where the regular inhabitants of limited depths terminate.

The Heterostegina-bed at Malta is not without smaller Foraminifers (some of which we can identify,—as the Globigerina bulloides, Truncatulina lobatula, &c.), but the matrix is too stubborn to yield all its treasures.

From a palæontological point of view the only part of a Foraminifer with which we have to deal is the shell or "test," […] Each bud of the compound Foraminifer is surrounded by its own shell, so that the whole comes to be composed of a number of chambers, each containing a mass of sarcode.

The environmental significance of foraminifer abundance variations in Arctic cores is controversial[…]. One interpretation concludes that foraminifer-rich intervals represent interglacial conditions reflecting seasonally absent or reduced ice cover leading to increased productivity; intervals barren or nearly barren of foraminifers are considered to represent glacial conditions with thicker ice cover and lower productivity[…].

A cross-section through a single agglutinated foraminifer – in this case, one that selected both carbonate and non-carbonate grains to build its test. These foraminifers are recognizable by the chamber-shaped grain arrangements rather than the otherwise random distribution of grains in the rest of the rock.

One of the most frequently asked questions concerns the predators of planktic foraminifers. Whereas a large variety of predators of benthic foraminifers have been identified, the nature of planktic foraminifer predators is largely enigmatic.