Daughter taxa (time control age-window is: 0-800Ma) | ||||
Planoheterohelix globulosa | ||||
Planoheterohelix moremani | ||||
Planoheterohelix olssoni | ||||
Planoheterohelix papula | ||||
Planoheterohelix paraglobulosa | ||||
Planoheterohelix planata | ||||
Planoheterohelix postmoremani | ||||
Planoheterohelix praenuttalli | ||||
Planoheterohelix reussi | ||||
Planoheterohelix rumseyensis | ||||
species here provisionally placed in Planohetorohelix | ||||
Planoheterohelix labellosa | ||||
Planoheterohelix sphenoides | ||||
Planoheterohelix stenopos | ||||
Planoheterohelix vistulaensis | ||||
Planoheterohelix sp. Specimens which cannot be assigned to established species |
Taxonomy
Original description: Description. Test is biserial throughout. Proloculus is small and followed by larger second chamber. Chambers are subglobular to globular in early portion of test and often reniform in adult. Periphery is broadly rounded. Aperture is a low- to medium-high arch situated at base of last-formed chamber; it is bordered by two symmetrically developed flanges. Chamber surface is smooth or with fine longitudinal costae in earlier species and completely costate in evolved ones. Test wall is calcitic, hyaline, microperforate to finely perforate. Pores are situated in intercostal spaces or they might penetrate and interrupt costae.
Entries in the Catalog of original descriptions: Planoheterohelix, Globoheterohelix
Distinguishing features:
Parent taxon (Heterohelicidae): Aperture symmetrical, ranging from a low slit to a high arch at the base of the final chamber, becoming terminal in uniserial taxa.
This taxon: Biserial throughout, aperture symmetrically positioned, wall texture costate.
Emended description:
Morphology:
Geological Range:
Last occurrence (top): at top of P. hariaensis zone (100% up, 66.4Ma, in Maastrichtian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within T. reicheli zone (98.69-98.85Ma, base in Cenomanian stage). Data source: Total of ranges of species in this database
Plot of range and occurrence data:
Planoheterohelix compiled by the pforams@mikrotax project team viewed: 5-10-2024
Short stable page link: https://mikrotax.org/pforams/index.php?id=110399 Go to Archive.is to create a permanent copy of this page - citation notes |
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