Test Surface Textures

Surface textures of foraminifera can vary quite significantly based on the composition (mentioned later), specific function, and overall geometry of the test. The surface of a foraminifera can be completely smooth or delicately complex. Growth of additional features on the exterior of the test is known as ornamentation. This term is somewhat deceiving in that this ornamentation is not merely decorative. There is no conceivable ecological need for decoration. Ornamentation is in fact a very important functional morphology whose evolution is based on selective adaptation to maximize a foraminifera's potential in a given ecological niche.

These are a series of photomicrographs depicting surface textures ranging from the simple and smooth through perforated, to a spiny, fine seive texture. These foraminifera are Sigmoidella ellegantissima, Heterolepa subhaidingeri, Parrellina hispidula, and Globigerinella siphonifera, respectively, as documented by (Loebelich, A.R. and Tappan, H. Foraminifera of the Sahul Shelf and Timor Sea).

Composition of the outer test is a very important factors when considering variations in descriptive morphology. The intricacy of surface sculpturing is limited by the medium with which it is created, specifically the mineralogy, and hence directly influences the overall appearance and geometry of the Foram. Go HOME to see further...