Twelve latest Maastrichtian planktic foraminiferal species of the genus Plummerita in the Late Maastrichtian P. hantkeninoides Range Zone are recorded and illustrated from the Northern and Southern Tethys (USA, Caribbean, Trinidad, Spain, Tunisia, Egypt, Iraq and India). Six planktic foraminiferal evolutionary lineages in the assemblage were produced by gradualistic evolutionary trends which observed within this assemblage. These trends are: (1) Plummerita elkefensis Anan and Orabi → P. hantkeninoides (Brönnimann), (2) P. safaae Anan, n. sp. → P. haggagae Anan, (3) P. salimi Anan, n. sp. → P. hodae Anan, (4) P. kellerae Anan and Orabi → P. caribbeanica Anan, (5) P. inflata (Brönnimann) → P. tunisica Anan, (6) P. costata (Brönnimann) → P. spainica Anan. Two of the recorded species is treated here as new: Plummerita safaae and P. salimi. These lineages help to define the major faunal changes in the Late Maastrichtian warm water Gene Pool.