NB These concise distinguishing features statements are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus. They are being edited as the site is developed and comments on them are especially welcome.
Description
Morphology: This species is relatively uncommon in the northwest Pacific, and it is markedly different from Globoconella inflata. In the northwest Pacific, Globoconella triangula is characterized by having 3–3.5 tightly coiled chambers in the final whorl, a flat to very low trochospire, and a very smooth test comparable to that of G. inflata in its later, more evolved forms. However, we note this species can have a more pustulose texture as illustrated by Scott et al. (1990). Umbilical chambers are highly vaulted which gives the species a very triangular outline in edge/axial view. Because these forms are distinct from typical G. inflata, we have elevated G. triangula to a species status. [Lam & Leckie 2020 p.203]
Biogeography and Palaeobiology
Biostratigraphic distribution
Geological Range: Notes: Theyer (1973) notes this form is absent in the Holcene Last occurrence (top): within Middle Pleistocene Sub-Epoch (0.13-0.78Ma, top in Ionian stage). Data source: Lam & Leckie 2020 First occurrence (base): within Late Pliocene Sub-Epoch (2.59-3.60Ma, base in Piacenzian stage). Data source: Lam & Leckie 2020
Plot of occurrence data:
Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
(NB There is no histogram as there are no occurrence records for the taxon in the Neptune database) Parent: Globoconella
Primary source for this page: Lam & Leckie 2020
References:
Chaisson, W. P. & Pearson, P. N. (1997). Planktonic foraminifer biostratigraphy at Site 925: Middle Miocene–Pleistocene. Proceedings of the Ocean Drilling Program, Scientific Results. 154: 3-31. gs
Kennett, J. P. & Srinivasan, M. S. (1983). Neogene Planktonic Foraminifera. Hutchinson Ross Publishing Co., Stroudsburg, Pennsylvania. 1-265. gs
Lam, A. & Leckie, R. M. (2020a). Late Neogene and Quaternary diversity and taxonomy of subtropical to temperate planktic foraminifera across the Kuroshio Current Extension, northwest Pacific Ocean. Micropaleontology. 66(3): 177-268. gs
Theyer, F. (1973). Globorotalia inflata triangula, a new planktonic foraminiferal subspecies. Journal of Foraminiferal Research. 3: 199-201. gs
Globoconella triangula compiled by the pforams@mikrotax project teamviewed: 14-12-2024