pforams@mikrotax - Pearsonites pforams@mikrotax - Pearsonites


Classification: pf_cenozoic -> Truncorotaloididae -> Pearsonites
Sister taxa: Alicantina, Acarinina, Praemurica ⟩⟨ Igorina, Pearsonites, Planorotalites, Astrorotalia ⟩⟨ Morozovella, Morozovelloides
Daughter taxa (time control age-window is: 0-800Ma)
Pearsonites sensu Soldan et al. 2014
Pearsonites anapetes
Like I. broedermanni but with more plano-convex test; more chambers (8-9) in final whorl; wider and deeper umbilicus; and tendency towards an intraumbilically restricted aperture.
Pearsonites broedermanni
Biconvex to planoconvex test with 6-7 chambers in fine whorl. Like I. lodoensis but with less lobulate periphery and flatter spiral side.
Pearsonites lodoensis
Test small, lobulate, equally biconvex, densely muricate; narrow umbilicu; essentially straight radial sutures on the umbilical side.


Citation: Pearsonites Soldan, Petrizzo & Premoli Silva 2014
taxonomic rank: Genus
Type species: Globorotalia (Truncorotalia) broedermanni Cushman & Bermudez, 1949
Taxonomic discussion: The species icluded here in Pearsonites were inlcuded in Igorina by Olsson et al. (2006). However, Soldan et al. (2011, 2014) argued that the genus was polyphytletic with the broedermanni group of species having evolved indepedantly from Acarinina.

Catalog entries: Pearsonites

Distinguishing features:
Parent taxon (Truncorotaloididae): Muricate
This taxon: small Morozovellids with biconvex–planoconvex tests with an overall rounded periphery

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.


Test low trochospiral, weakly biconvex to planoconvex, with 6–10 chambers in the last whorl. Spiral side with subglobular to subquadrate chambers that increase very gradually in size; sutures slightly depressed to flush and slightly recurved to oblique. Umbilical side with triangular chambers; sutures nearly straight, depressed. Umbilicus generally widely bordered by coalescing circumumbilical muricae. Aperture a low arch extending toward the peripheral margin that is subrounded to subangular. [Soldan et al. 2014]

Wall type:
Nonspinose with thin muricae.

Biogeography and Palaeobiology

Most likely ancestor: Acarinina - at confidence level 4 (out of 5). Data source: Soldan et al 2011, Soldan et al 2014 (fig. 2).

Biostratigraphic distribution

Geological Range:
Last occurrence (top): at top of E9 zone (100% up, 43.2Ma, in Lutetian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within P5 zone (55.96-57.10Ma, base in Thanetian stage). Data source: Total of ranges of species in this database

Plot of occurrence data:


Soldan, D. M., Petrizzo, M. R., Silva, I. P. & Cau, A. (2011). Phylogenetic relationships and evolutionary history of the Paleogene genus through parsimony analysis. Journal of Foraminiferal Research. 41: 260-284. gs

Soldan, D. M., Petrizzo, M. R. & Silva, I. P. (2014). Pearsonites, a new Paleogene planktonic foraminiferal genus for the broedermanni lineage. Journal of Foraminiferal Research. 44: 17-27. gs


Pearsonites compiled by the pforams@mikrotax project team viewed: 17-7-2024

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