pforams@mikrotax - Hantkenina lehneri

pforams@mikrotax - Hantkenina lehneri pforams@mikrotax - Hantkenina lehneri

Hantkenina lehneri

Classification: pf_cenozoic -> Hantkeninidae -> Hantkenina -> Hantkenina lehneri
Sister taxa: H. nanggulanensis, H. alabamensis, H. primitiva, H. compressa, H. australis, H. dumblei ⟩⟨ H. lehneri, H. liebusi, H. mexicana, H. singanoae, H. sp.

Eocene_Atlas_pl08-8_fig6-8.jpg
Eocene_Atlas_pl08-8_fig9-11.jpg
Eocene_Atlas_pl08-8_fig13.jpg
Eocene_Atlas_pl08-8_fig2-4-12.jpg
Eocene_Atlas_pl08-8_fig3-5.jpg

Taxonomy

Citation: Hantkenina lehneri Cushman & Jarvis 1929

taxonomic rank: Species

Basionym: Hantkenina lehneri

Synonyms:

Hantkenina lehneri Cushman and Jarvis, 1929:16, pl. 3: fig. 8 [Eocene, Lowest marl, Moruga River, Trinidad].— Subbotina, 1953:142 [middle Eocene Acarinina Zone, northern Caucasus].—Raju, 1968:290, pl. 1: fig. 3 [middle Eocene Globigerina frontosa zone, Karaikal, Cauvery Basin, India].
Hantkenina (Aragonella) lehneri Cushman and Jarvis.— Brönnimann, 1950:408, pl. 55: figs. 7-8 [lower and middle Eocene, Navet Fm., Moruga River, Trinity Hill Reserve, Trinidad].
Not Hantkenina (Aragonella) lehneri Cushman and Jarvis.— Ramsay, 1962:83, pl. 16: figs. 2, 5, 15 [lower and middle Eocene, Kilwa Masoko, Tanzania] (= H. mexicana).

Taxonomic discussion: The distinctive morphology represented by Cushman and Jarvis’s holotype specimen (H. lehneri s. s.) is rare (Pl.8.8, Figs. 2, 12). We suggest that most forms recorded as H. lehneri in deep-sea core material are a closely related variant. These more commonly encountered forms also possess elongate final chambers and an incised peripheral outline. However, the test of the latter morphotype is strongly laterally compressed and the early chambers of the final whorl are more closely appressed than in the Cushman and Jarvis holotype. At the present time there are insufficient data to justify the erection of a new species and we include them in H. lehneri. [Coxall & Pearson 2006]

Catalog entries: Hantkenina lehneri

Type images:

holotype: H. lehneri

Distinguishing features:
Parent taxon (Hantkenina): Final chambers with tubulospines
This taxon: Final chambers elongate with tubulospines in forward position; peripheral outline distinctly stellate. 5-6 chambers in the final whorl.

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, involute,
biumbilicate, 4½-6 appressed chambers in the final whorl, increasing rapidly in size as added; early chambers are subtriangular, final 2-3 chambers radially elongated and ‘finger-like’, each chamber of the adult whorl extends into a hollow tubulospine; peripheral outline is deeply incised, stellate; aperture is an elongated equatorial arch extending halfway up the apertural face, bordered by a well pronounced imperforate lip, which is often pustulose and crenulated along its margin; sutures are depressed, straight, becoming curved, web-like remnants of apertural lips sometimes present along sutures; umbilical region shallow, commonly pustulose, pustules extending to early chambers of final whorl; tubulospines broad based, directed radially and positioned forward of the central chamber axis toward the anterior chamber suture, posterior chamber shoulder longer than the anterior shoulder; tubulospines are not preserved in the holotype but are assumed to be comparable to those of H. liebusi and H. mexicana. [Coxall & Pearson 2006]

Wall type:

Smooth, normal perforate,
probably nonspinose. [Coxall & Pearson 2006]

Size:

Length (excluding tubulospines) up to 1 mm (Cushman and Jarvis,1929). [Coxall & Pearson 2006]

Character matrix
test outline: Stellate chamber arrangement: Planispiral edge view: Compressed aperture: Equatorial
sp chamber shape: Elongate coiling axis: N/A periphery: Tubulospines aperture border: N/A
umb chbr shape: Elongate umbilicus: Wide periph margin shape: Subangular accessory apertures: None
spiral sutures: Strongly depressed umb depth: Shallow wall texture: Smooth shell porosity: Finely Perforate: 1-2.5µm
umbilical or test sutures: Strongly depressed final-whorl chambers: 5-6 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology

Geographic distribution

Hantkenina lehneri s.str. has been found in Trinidad and Tanzania. Flattened forms referable to the species have been recorded in the Northern Caucasus Mts. of Russia, Southern India and ODP Site 865, often in Zone E9 in association with Morozovelloides lehneri. [Coxall & Pearson 2006]
Aze et al. 2011 summary: Found in TrinidadTanzania and Russia; based on Coxall & Pearson (2006)

Isotope paleobiology

No data available. [Coxall & Pearson 2006]
Aze et al. 2011 ecogroup 3 - Open ocean thermocline; based on comparison with other species of the genus.

Phylogenetic relations

Hantkenina lehneri probably evolved from H. liebusi by an increase in the number of chambers in the final whorl (more evolute growth spiral), a shift of the tubulospines towards the anterior suture and an increase in radial chamber height. [Coxall & Pearson 2006]

Most likely ancestor: Hantkenina liebusi - at confidence level 4 (out of 5). Data source: Coxall & Pearson (2006) fig 8.1.

Biostratigraphic distribution

Geological Range:
Notes: Middle Eocene. Zone E9-E11. [Coxall & Pearson 2006]
Last occurrence (top): in upper part of E11 zone (60% up, 41Ma, in Bartonian stage). Data source: Coxall & Pearson (2006) fig 8.1
First occurrence (base): in upper part of E9 zone (60% up, 43.5Ma, in Lutetian stage). Data source: Wade et al. (2011), fig. 6

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
Histogram - Neptune occurrence data from DSDP and ODP proceedings. Pale shading <50 samples in time bin. Interpret with caution & read these notes
Taxon plotted: Hantkenina lehneri, synonyms included - Globorotalia lehneri; Globorotalia lehneri (q); Hantkenina lehneri; Morozovella lehneri; Morozovelloides lehneri;
See also space-time plot :: Samples map :: Parent: Hantkenina

Primary source for this page: Coxall & Pearson 2006 - Eocene Atlas, chap. 8, p. 237

References:

Brönnimann, P. (1950b). The Genus Hantkenina Cushman in Trinidad and Barbados, B. W. I. Journal of Paleontology. 24(4): 397-420. gs

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. gs O

Cushman, J. A. & Jarvis, P. W. (1929). New foraminifera from Trinidad. Contributions from the Cushman Laboratory for Foraminiferal Research. 5: 6-17. gs

Raju, D. S. N. (1968). Eocene-Oligocene planktonic foraminiferal biostratigraphy of Cauvery Basin, South India. Memoir of the Geological Society of India. 2: 286-299. gs

Ramsay, W. R. (1962). Hantkeninidae in the Tertiary rocks of Tanganyika. Contributions from the Cushman Foundation for Foraminiferal Research. 13(3): 79-89. gs

Hantkenina lehneri compiled by the pforams@mikrotax project team viewed: 4-10-2024

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test outline:	Stellate	chamber arrangement:	Planispiral	edge view:	Compressed	aperture:	Equatorial
sp chamber shape:	Elongate	coiling axis:	N/A	periphery:	Tubulospines	aperture border:	N/A
umb chbr shape:	Elongate	umbilicus:	Wide	periph margin shape:	Subangular	accessory apertures:	None
spiral sutures:	Strongly depressed	umb depth:	Shallow	wall texture:	Smooth	shell porosity:	Finely Perforate: 1-2.5µm
umbilical or test sutures:	Strongly depressed	final-whorl chambers:	5-6	N.B. These characters are used for advanced search. N/A - not applicable