Four and five-chambered evolution of the late maastrichtian planktic foraminiferal Plummerita species in the Tethys

Abstract

Brönnimann1 proposed two groups from Trinidad, which have spine-like prolongation of ultimate and penultimate chambers of the diagnostic latest Maastrichtian planktonic foraminiferal genus Plummerita. As a separate group of this genus, some of it has the last six-chambered volition in Plummerita reicheli group (P. reicheli, P. pustulata, and P. hexacamerata). The same author also proposed another group related to this genus, with the last five-chambered volution: P. hantkeninoides group (P. hantkeninoides, P. costata and P. inflata). Nonetheless, another third group was also added to these Plummerita assemblages, where Anan2 added a distinct species of Plummerita from the Duwi section, the Red Sea coast of Egypt, P. haggagae, which differs from the other species of the Plummerita by its four-chambered volution in the last whorl. In the current study, an attempt is made to identify three new species of the planktic foraminiferal assemblages of five-chambers volution, P. hantkeninoides group (P. hodae, P. kellerae, P. premolisilvae) is believed here to be new, as well as another one four-chamber volution, P. haggagae group (P. elkefensis, n. sp.), which described from many localities in the Southern Tethys (Tunisia, Egypt, Iraq), and Northern Tethys (Italy). The biostratigraphy, paleogeography, paleoecology, and paleobathymetry of the recorded Plummerita members in different Tethyan localities are presented and discussed.