A chronocladogeny and corresponding classification of Neogene planktic foraminifera with a documentation of morphotypes from two Pacific deepsea stratigraphic sections

Abstract

Two deepsea stratigraphic sections with highly complete oozes from the Middle Miocene to Pleistocene, located on the north Lord Howe Rise and the east equatorial Pacific, have been sampled at coarse intervals. Large assemblages of planktic foraminifera, recovered from each sample, have been examined to determine sets of morphologically intragrading fossil populations and morphologically distinctive individuals, i.e. morphotypes. Each fossil population is interpreted as a remnant of ancient sets of interbreeding living populations, i.e. species. On the basis of previous literature on morphotype phylogeny, a cladogeny with biostratigraphic control is constructed and transferred to a chronologic scale. This chronocladogeny is tentatively extended to the base of the Tertiary and integrated into a phylogenetic scheme for planktic foraminifera, starting with their Triassic origin. A classification is derived from the cladogeny by assigning each segment to the rank of species and recognizing all possible multitypic and necessary monotypic taxa. Of the supraspecific taxa generated, only genus-group categories are formalized. The following taxa are introduced: Streptochilus tokelauae flexiserialis n.subsp., S. globiger infirmirugosus n.subsp., Tenuitella postcretacea pieste n.subsp., Toddella n.gen., T. grata compressa n.subsp., Tinophodella (Tenuirotalia) n.subgen., T. (T.) praemonita n.sp., T. (T.) praemonita praemonita n.subsp., T. (T.) praemonita tetrapetala n.subsp., T. (T.) praemonita tripetala n.subsp., T. (Parkerina) n.subgen., T. (Tinophodella) antarctica polypetala n.subsp., T. (T.) evoluta n.sp., T. (T.) evoluta evoluta n.subsp., T. (T.) uvula quasifoliata n.subsp., Globorotaloides (Bandyus) n.subgen., G. (B.) relizensis extraumbilicata n.subsp., G. (Globorotaloides) variabilis anasuteri n.subsp., G. (G.) dinapoli redissimilis n.subsp., G. (G.) dinapoli anavenezuelana n.subsp., Globoquadrina (Globoquadrina) tripartita laxispira n.subsp., G. (G.) tripartita tricamerata n.subsp., G. (Neoacarinina) conglomerata ventriosa n.subsp., Turborotalita detrita primoripumilio n.subsp., T. detrita sinecristata n.subsp., Globigerinopsis aquasagaensis moderiapertura n.subsp., Hastigerina (Bollius) n.subgen., H. (Globigerinella) evoluta n.sp., H. (G.) evoluta evoluta n. subsp., Orbulina (Globigerinoides) haitiensis compacta n.subsp., O. (G.) haitiensis progomitula n.subsp., O. (G.) haitiensis praerubra n.subsp., O. (G.) haitiensis epityche n.subsp., O. (G.) haitiensis anterubra n.subsp., O. (G.) conglobata compressa n.subsp., O. (G.) conglobata altihelix n.subsp., O. (Orbulina) trilocularis incrusta n.subsp., O. (O.) trilocularis alpha n.subsp., Leroyellus n.gen., L. bulbosus trisphaera n.subsp., Sphaeroidinella dehiscens reticulata n.subsp., Globigerina (Citapremolia) n.subgen., G. (Ehrenbergellus) n.subgen., G. (Globigerina) concinna opsionepenthoides n.subsp., G. (G.) concinna altihelix n.subsp., G. (G.) cincinna anapetes n.subsp., G. (G.) bulloides incrusta n.subsp., G. (G.) bulloides extensa n. subsp., Pulleniatina siakensis umbilicata n.subsp., P. siakensis plana n.subsp., P. siakensis juvenis n.subsp., P. helicina polygonia n.subsp., P. helicina rictus n.subsp., P. helicina congesta n.subsp., Blowellus n.gen., Finlaynus n.gen., F. miozea acuimarginata n.subsp., Cushstainius n.gen., Hirsutella (Ognibenius) n.subgen., H. (0.) ventriosa astricticamerata n.subsp., H. (0.) ventriosa evexa n.subsp., H. (Deshayesulus) n.subgen., H. (D.) punaticulata obturoapertura n.subsp., Dorbignyus n.gen., D. limbatus latiumbilicatus n.subsp., D. limbatus confertus n.subsp., D. limbatus oregope n.subsp., D. limbatus consutilus n.subsp., Globoconella sphericomiozea capitona n.subsp., Falsella n.gen., F. spuritumida n.sp., F. spuritumida spuritumida n.subsp., Truncorotalia (Cushartius) n.subgen., T. (C.) crassula complanata n.subsp., T. (Gallerius) n.subgen., T. (Truncorotalia) tosaensis akrotenes n.subsp., T. (T.) pseudocrassa hybrida n.subsp. The following new names are needed: Toddella grata quiltyi n.name for Globorotalia (Turborotalia) akersi Quilty and Globigerina (Globigerina) bulloides broennresigi n.name for Globorotalia (Turborotalia) incisa Brönnimann & Resig. Morphotypes are relegated to informal status and form a system of names separate from but capable of integration with the formal categories.