THE EVOLUTIONARY LINEAGES OF THE MAASTRICHTIAN PLANKTIC FORAMINIFERA GENUS Plummerita IN THE TETHYS.

Five phylogenetic lineages were observed by present author in the eleven Tethyan Maastrichtian planktic foraminiferal species of the genus Plummerita. These lineages help to define the major faunal changes from the species throughout of three groups of the Plummerita. The first group (P. haggagae group) belongs to the four-chambered volition (4-ch) with axially pointed spine-like prolongation evolved to another species of five-chambered volition (5-ch) (P. hantkeninoides group), to another species of six-chambered volition (6-ch) (P. reicheli group). The five lineages are: (1) The Plummerita elkefensis (4-ch) to P. hantkeninoides (5-ch), (2) P. haggagae (4-ch) to P. costata (5-ch) to P. spainica (6-ch), (3) P. inflata (5-ch) to P. tunisica (6-ch) (4) P. kellerae (5-ch) to P. caribbeanica (6-ch), (5) P. premolisilvae (5-ch) to P. reicheli (6-ch). Unfortunately, most of these lineage are uncompleted from four to five to six-chamber volution, while only one of them is completed (no. 2). In spite of this uncompleted lineages situation, it seems that we must await further study to complete these lineages by another unknown taxa. [ABSTRACT FROM AUTHOR]