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Hantkenina lehneri Cushman & Jarvis 1929 from: Pearson, P.N.Olsson, R.K.Hemleben, C.Huber, B.T.Berggren, W.A. (2006): Atlas of Eocene Planktonic Foraminifera. p. 1-513
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Anonymous: Unedited TaxonConcept data
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Species Hantkenina lehneri Cushman & Jarvis 1929


Alternative name:
Diagnosis / Definition:
Pearson et al. (2006):
DESCRIPTION. Type of wall: Smooth, normal perforate, probably nonspinose. Test morphology: Planispiral, involute, biumbilicate, 4 1/2-6 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. Size: Length (excluding tubulospines) up to 1 mm (Cushman and Jarvis,1929).
Discussion / Comments:
Pearson et al. (2006):
DISTINGUISHING FEATURES.- Hantkenina lehneri is distinguished from H. liebusi by having cylindrical, finger-like chambers in the latest growth stages, a more deeply incised and more stellate peripheral outline and, on average, one more chamber in the final whorl. It differs from H. dumblei by the higher aspect ratio of the final chambers and the more deeply incised peripheral outline. The finger-like chambers of this species are reminiscent of early examples of H. mexicana. H. lehneri can be distinguished from the earlier morphotype by the longer sutures, unequal chamber shoulders and more slender tubulospines. DISCUSSION.- The distinctive morphology represented by Cushman and Jarvis's holotype specimen l (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 l 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. PHYLOGENETIC RELATIONSHIPS.- 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. STRATIGRAPHIC RANGE.- Middle Eocene. Zone E9-Ell. 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. STABLE ISOTOPE PALEOB1OLOGY.- No data available.
Systematics:

35
 Ordo Foraminiferida
  Superfamilia Globigerinaceae
   Familia Guembelitriidae
    Genus Jenkinsina
     Species Hantkenina lehneri
      Species Jenkinsina columbiana
Synonym list:
Pearson et al. (2006):
1929 Hantkenina lehneri Cushman & Jarvis. - Cushman & Jarvis : p.16 pl. 3; fig. 8 [Eocene, Lowest marl, Moruga River, Trinidad]
1950 Hantkenina (Aragonella) lehneri Cushman & Jarvis. - Brönnimann : p.408 pl. 55; fig. 7-8 [lower and middle Eocene, Navet Fm., Moruga River, Trinity Hill Reserve, Trinidad]
1953 Hantkenina lehneri Cushman & Jarvis. - Subbotina : p.142 [middle Eocene Acurinina Zone, northern Caucasus]
non 1962 Hantkenina (Aragonella) lehneri Cushman & Jarvis. - Ramsay : p.83 pl. 16; fig. 2, 5, 15 [lower and middle Eocene, Kilwa Masoko, Tanzania]; (= H. mexicana)
1968 Hantkenina lehneri Cushman & Jarvis. - Raju : p.290 pl. 1; fig. 3 [middle Eocene Globigerina frontosa zone, Karaikal, Cauvery Basin, India]
2006 Hantkenina lehneri Cushman & Jarvis. - Pearson et al. : p.240 pl. 8.8; fig. 1-15 (Pl. 8.8, Fig. 1 : original illustration of the holotype of Hantkenina lehneri Cushman and Jarvis)
Specimen:
Cushman Collection - Smithsonian Museum of Natural History, Washington, D.C., Inventory number: USNM 10071
References:

Cushman,J.A. and Jarvis,P.W. (1929):
New foraminifera from Trinidad . Contributions from the Cushman Foundation for Foraminiferal Research Vol. 5 p. 6-17

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

Subbotina,N.N. (1953):
Fossil foraminifera of the USSR. Globigerinidae, Hantkeninidae and Globorotaliidae [in Russian] . Trudy Vsesoyuznogo Neftyanogo Nauchno-Isledovatelskogo Geologo-Razvedochnogo Instituta (VNIGRI), Novaya Seriya Vol. 76 p. 1-296

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

Raju,D.S.N. (1968):
Eocene-Oligocene planktonic foraminiferal biostratigraphy of Cauvery basin, South India . Memoires of the Geological Society of India Vol. 2 p. 286-289

Pearson,P.N.; Olsson,R.K.; Hemleben,C.; Huber,B.T. and Berggren,W.A. (2006):
Atlas of Eocene Planktonic Foraminifera. p. 1-513
Anonymous: Unedited TaxonConcept data
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