ABSTRACT

Through several decades of research on Foraminiferida and revision of generic and suprageneric classification, the nature of coiling patterns and modes of growth and their proper role in interpreting shell architecture generally have been misunderstood. Much of this confusion is due to the poorly chosen or unfortunate descriptive language used in earlier classifications, especially those of Cushman (1925, 1927, 1928, 1933, 1940, 1948).

Biseriality and triseriality, are, in fact, spiral growth patterns. The radius and the amplitude of the spiral in conjuction with chamber diameter and the rate of increase in chamber size are among the most important factors affecting shell architecture, especially in forms with helical growth patterns. The nature of the abrupt change in chamber addition which occurs between the final chamber in the juvenarium and the first added in the adult series of chambers should be recognized as another primary factor in generic discrimination and classification.

Planispiral and helical growth patterns are of fundamental importance in interpreting suprageneric relationships within the Foraminiferida. Thus, more accurate language and more meaningful descriptions of shell architecture and growth modes will enhance the understanding of generic and suprageneric differences among professional micropaleontologists as well as greatly assisting the beginning student.