Daughter taxa (time control age-window is: 0-800Ma)
Granddaughter taxa
Rectoguembelina Transition from biserial to uniserial portion of test very abrupt, occurring after first four or more pairs of biserial chambers, without an intervening interval of gradually increasing chamber overlap. Apertures on biserial portion interiomarginal with a small, narrow arch; apertures on uniserial chambers terminal, circular, and aligned in rectilinear fashion, without lip or toothplate. Wall calcareous, microperforate; surface smooth to finely pustulose.
Citation: Heterohelicidae Cushman, 1927taxonomic rank: FamilyTaxonomic discussion: Only simple, biserial forms survived into the Cenozoic. The latter portion of the test often becomes uniserial. [Olsson et al. 1999]
Distinguishing features: Parent taxon (Guembelitrioidea): Biserial, enrolled biserial and triserial taxa. Wall microperforate. This taxon: Test biserial, may become multiple or uniserial; chambers, globular to ovoid in shape; wall smooth or with parallel ridges; aperture, a low, symmetrical arch, usually at base of last chamber, may have accessory sutural apertures.
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
Biogeography and Palaeobiology
Biostratigraphic distribution
Geological Range: Last occurrence (top): at top of E14 zone (100% up, 35.9Ma, in Priabonian stage). Data source: Total of ranges of the species in this database First occurrence (base): within A. mayaroensis zone (67.3-69.18Ma, base in Maastrichtian stage). Data source: Total of ranges of species in this database
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
Neptune data: this is a higher taxon page so Neptune data is not plotted. For the customisable plot option go to a genus page Parent: Guembelitrioidea
Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 93
References:
Cushman, J. A. (1927a). An outline of a re-classification of the Foraminifera. Contributions from the Cushman Laboratory for Foraminiferal Research. 3: 1-105. gsO
Huber, B. T., Olsson, R. K. & Pearson, P. N. (2006). Taxonomy, biostratigraphy, and phylogeny of Eocene microperforate planktonic foraminifera (Jenkinsina, Cassigerinelloita, Chiloguembelina, Streptochilus, Zeauvigerina, Tenuitella, and Cassigerinella) and Problematica (Dipsidripella). In, Pearson, P. N., Olsson, R. K., Hemleben, C., Huber, B. T. & Berggren, W. A. (eds) Atlas of Eocene Planktonic Foraminifera. Cushman Foundation for Foraminiferal Research, Special Publication . 41(Chap 16): 461-508. gsO
Heterohelicidae compiled by the pforams@mikrotax project teamviewed: 3-12-2023
