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Hedbergella aptiana


Classification: pf_mesozoic -> Hedbergellidae -> Hedbergella -> Hedbergella aptiana
Sister taxa: H. aptiana, H. bizonae, H. bollii, H. compacta, H. excelsa, H. gorbachikae, H. handousi, H. hexacamerata, H. hispaniae, H. infracretacea, H. kuhryi, H. kuznetsovae, H. labocaensis, H. luterbacheri, H. maslakovae, H. mitra> >>

Taxonomy

Citation: Hedbergella aptiana Bartenstein 1965
Taxonomic rank: species
Basionym: Hedbergella aptiana
Synonyms:
Taxonomic discussion: This taxon shows a rather wide morphological variability mainly regarding the number of chambers in the final whorl, usually ranging from 5 to 5.5 (even if rare 4.5-chambered juveniles as well as few 6-chambered morphotypes have been also observed) and the course of the peripheral outline which can be more or less slightly lobate. [Huber & Leckie, 2011, p. 65]: Remarks. Although Hd. aptiana was not described as having perforation cones, and Banner and others (1993) explicitly noted their absence, SEM observation of well preserved specimens reveals their faint expression on all but the last of the final whorl chambers (Fig. 5.6). Absence of any periumbilical structures is apparent on the wellpreserved specimens. Hedbergella aptiana differs from Hd. occulta by having faster chamber growth rate, lacking deeply incised umbilical sutures, and lacking an apertural lip. It differs from Hd. infracretacea by having a smoother test surface and a faster growth rate of the chambers. [copied from Chronos database]

Type images:

Original description: Diagnose. - Eine Hedbergella-Art mit langlich-ovalem Gehäuse und nur schwach ausgeprägter Spiralseite mit 2 Windungen, mit 5 Kammern in der letzten Windung und mit ungleichmässiger , länglich-ovaler End kammer, die vorn stumpfwinkelig gekantet ist.

Beschreibung. - Gehäuse kalkig-perforat, langlich-oval, mit 5 Kammern in der Umbilikalseite und 14 Kammern in der Spiralseite, von diesen nur die letzten 10 Kammern wohlausgeprägt. Gehäusequerschnitt flach-trochospiral, keine Seite stärker herausgewölbt. Kammern kugelig bis auf die Endkammer, die Unglich-oval unregelmässig gewachsen und vorn stumpfwinkelig gekantet ist. Nähte auf der Umbilikalseite stärker eingetieft als auf der Spiralseite. Spiralseite mit 2 Windungen. Umbilikus länglich. Mündung interiomarginal. Wanelungen etwas rauh.

Entries in the Catalog of original descriptions: Hedbergella aptiana, Blefuscuiana aptiana orientalis


Emended description:

Test medium, coiled in a flat to slighlty depressed trochospire; 2 to 2.5 whorls; 5 to 5.5 chambers in the outer whorl (rare juveniles with 4.5 chambers) increasing rather rapidly in size as added; chambers globular to subglobular, inflated; equatorial periphery ovoid, slightly to moderately lobate; sutures depressed, radial to slightly curved; umbilical area rather wide and shallow; aperture as a low to medium arch bordered by a lip. Wall smooth, finely perforate, that may be covered by perforation cones in the early chambers of the last whorl. [Huber & Leckis, 2011, P.65]: Emended description. Test wall finely perforate, pores widely dispersed and surrounded by small perforation cones, surface mostly smooth. The shell may have fine pustules concentrated in umbilical region. Test medium in size, coiled in 2 to 2.5 whorls with a flat to low trochospire; 5 to 5.5 globular to subglobular chambers in the final whorl, increasing moderately in size; equatorial periphery elliptical, moderately lobate; sutures depressed, radial to slightly curved; umbilicus shallow, moderately wide; aperture a low to medium extraumbilical arch with a thin imperforate rim and without any periapertural structures. [copied from Chronos database]

Character matrix
test outline:Lobatechamber arrangement:Trochospiraledge view:Equally biconvexaperture:-
sp chamber shape:Inflatedcoiling axis:Lowperiphery:N/Aaperture border:Thin lip
umb chbr shape:Inflatedumbilicus:Narrowperiph margin shape:Broadly roundedaccessory apertures:N/A
spiral sutures:Strongly depressedumb depth:Shallowwall texture:Perforation conesshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Strongly depressedfinal-whorl chambers:5-5.5 N.B. These characters are used for advanced search. N/A - not applicable

Geological Range:
Last occurrence (top): within P. rohri zone (113.22-116.60Ma, top in Aptian stage). Data source: Banner et al., 1997
First occurrence (base): within H. similis zone (124.40-126.01Ma, base in Barremian stage). Data source: [copied from Chronos database]

Plot of range and occurrence data:

References:

Banner, F. T., Copestake, P. & White, M. R. (1993). Barremian-Aptian Praehedbergellidae of the North Sea area: a reconnaisance. Bulletin of the Natural History Museum, London (Geology). 49: 1-30. gs

Bartenstein, H. (1965). Taxonomische revision und nomenklatur zu Franz E. Hecht "Standard-Gliederung der Nordwest-deutschen Unterkriede nach Foraminiferen" (1938). Teil 4, Alb, mit Beschreibungen von Arten aus verschiedenen Unterkreide-Niveaus. Senckenbergiana Lethaea. 46: 327-366. gs

Huber, B. T. & Leckie, R. M. (2011). Planktic foraminiferal species turnover across deep-sea Aptian/Albian boundary sections. Journal of Foraminiferal Research. 41: 53-95. gs

Premoli Silva, I. & Verga, D. (2004). Practical Manual of Cretaceous Planktonic Foraminifera. In, Verga, D. & Rettori, R. (eds) International School on Planktonic Foraminifera. Universities of Perugia and Milano, Tipografia Pontefelcino, Perugia. 1-283. gs

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Hedbergella aptiana compiled by the pforams@mikrotax project team viewed: 21-1-2025

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