Citation: Hantkeninidae Cushman 1927taxonomic rank: FamilyType species: Hantkenina Cushman, 1924Taxonomic discussion: Cushman’s original broad description of the Family Hantkeninidae was such that almost any smaller foraminifer with planispiral coiling could be placed within it, and previous classifications have variously included Hastigerina, Pseudohastigerina and Schackoina in addition to Hantkenina (e.g., Cushman, 1948; Bolli and others, 1957). Although it is now known that these genera are unrelated, it is desirable to retain the Family in emended form to unite the middle to upper Eocene genera Clavigerinella, Hantkenina and Cribrohantkenina, which constitute a clearly defined monophyletic clade with a distinctive wall texture (Coxall and others, 2003; Hemleben and Olsson, Chapter 4, this volume). Although all species in this Family possess planispirally coiled shells, early members, e.g., Clavigerinella spp., Hantkenina singanoae n. sp. and H. mexicana, show some asymmetry (pseudo-planispirality) in side and apertural views, whereas later forms, e.g., H. dumblei, H. alabamensis and Cribrohantkenina inflata, possess a fully planispiral shell with strong symmetry across the mid-line. It is noteworthy that although it ultimately had a trochospiral ancestor, the complex multiple aperture system of Cribrohantkenina is usually bilaterally symmetrical across the equatorial plane, while being very variable between individuals, suggesting truly planispiral morphogenetic programming. [Coxall & Pearson 2006]
Distinguishing features: Parent taxon (pf_cenozoic): This is a polyphyletic grouping including all Cenozoic planktonic foraminifera This taxon: Planispiral, wall smooth
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: Planispiral or ‘pseudo-planispiral’ coiling; early chambers rounded, becoming digitate/clavate, triangular, polygonal, or spherical in the adult stages, laterally compressed or highly inflated; primary aperture a single narrow, symmetrical equatorial arch, bordered by an imperforate lip, accompanied or replaced by one or more additional areal apertures in the final 1-3 chambers (Cribrohantkenina); adult chambers of Hantkenina and Cribrohantkenina extend into a pronounced terminal nub or well-developed hollow tubulospine, projecting radially or at a low angle with respect to the chamber periphery in the direction of coiling. [Coxall & Pearson 2006] Wall type: Normal perforate, Clavigerinella-type wall, smooth or weakly cancellate; some species possibly sparsely spinose. [Coxall & Pearson 2006]
Biogeography and Palaeobiology
Most likely ancestor:Globigerinidae - at confidence level 3 (out of 5). Data source: The ancestor of Clavigerinella is now thought to be Subbotina.
Biostratigraphic distribution
Geological Range: Last occurrence (top): at top of E16 zone (100% up, 33.9Ma, in Priabonian stage). Data source: Total of ranges of the species in this database First occurrence (base): within E7a subzone (48.31-50.20Ma, base in Ypresian 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: pf_cenozoic
Primary source for this page: Coxall & Pearson 2006 - Eocene Atlas, chap. 8, p. 214
References:
Coxall, H. K. & Pearson, P. N. (2006). Taxonomy, biostratigraphy, and phylogeny of the Hantkeninidae (Clavigerinella, Hantkenina and Cribrohantkenina). 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 8): 213-256. gsO
Cushman, J. A. (1927e). Some characteristic Mexican fossil foraminifera. Journal of Paleontology. 1(2): 147-172. gs
Hantkeninidae compiled by the pforams@mikrotax project teamviewed: 19-9-2024
