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Species Clavigerinella jarvisi Cushman 1930 | ||||||
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| Diagnosis / Definition: | ||||||
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Pearson et al. (2006): DESCRIPTION. Type ofwall: Usually smooth, normal perforate, sometimes weakly cancellate; possibly spinose in life. Test morphology: Planispiral or pseudoplanispiral, evolute, biumbilicate or showing a slightly raised spiral side and very shallow umbilicus; 4-4112 chambers in the final whorl; increasing rapidly in size as added, early chambers rounded, final 2-3 chambers rapidly elongating into slender, cylindrical fingers (digitate); distal chamber ends smooth and rounded or slightly tapered; equatorial high arched aperture, symmetrical or slightly asymmetrical, bordered by a broad imperforate lip; sutures shallow, straight, becoming curved in later stages, short compared to the overall chamber length. Size: Up to 0.545 mm (Cushman, 1930). Detached chambers can be 0.40 mm, suggesting some specimens are as large as 1 mm. |
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| Discussion / Comments: | ||||||
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Pearson et al. (2006): DISTINGUISHING FEATURES.- The adult chambers of this species are significantly longer and more slender than in C. eocanica and C. caucasica and lack the terminal swellings of C. akersi. Clavigerinella jarvisi differs from "Clavatorella " nazcaensis Quilty in the larger size and more regular pattern of size increase of the chambers in the final whorl. It is comparable to Cretaceous Clavihedbergella watersi but has less bulbous chambers and a non-pustulose wall. DISCUSSION.- Blow (1979) did not subdivide Clavigerinella based on chamber length, believing this character to be a function of growth stage and environmental factors, helgce he placed C. jarvisi in synonymy with C. eocanica. Our observations of Clavigerinella from a number of sites (ODP Sites 865, 960, 121 8, Kane 9-C) indicate that a C. jarvisi morphotype with long finger-like chambers can be distinguished from the moderately clavate form C. eocanica. Complete specimens of this species are extremely rare and it is usually recognised by the detached digitate adult chambers, which are easily recognized by the porous chamber surface and remnants of the apertural arch (PI. 8.2, Figs. 8, 9). We find no evidence for the presence of "roughened projections" representing spine bases as indicated by Cushman's (1930) original description and find no link to the modem digitate form Hastigerinella digitata. PHYLOGENETIC RELATIONSHIPS.- This species probably evolved from C. eocanica in uppermost Zone E7 by extension and tapering of the final chambers. STRATIGRAPHIC RANGE.- Zone E7-E 10. Last occurrence poorly constrained. GEOGRAPHIC DISTRIBUTION.- Worldwide in low and mid-latitudes. Rare in oligotrophic open ocean sections, occasionally common in upwelling assemblages. Based on the occurrence of common C. jarvisi (recorded as C. eocanica) together with radiolarian-rich sediments in Peru and Ecuador, Stainforth (1948) suggested this species thrived in the cold waters of northward flowing ex-polar currents. His claim that this species is a strictly cold-water specialist cannot be substantiated, however, since it has never been found in polar regions. More likely, the occurrence of C. jarvisi was linked to western continental margin upwelling. STABLE ISOTOPE PALEOB1OLOGY.- No data available. |
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| Systematics: | ||||||
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24 Genus Clavigerinella Species Clavigerinella jarvisi 35 Ordo Foraminiferida Superfamilia Globigerinaceae Familia Hantkeninidae Genus Clavigerinella Genus Hantkenina Species Clavigerinella jarvisi Species Hantkenina alabamensis |
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| Synonym list: | ||||||
| Bolli (1957): 1930 Hastigerinella jarvisi Cushman. - Cushman : p. 18 pl. 3, figs. 8-11
1930 Hastigerinella eocanica var. aragonensis Nuttall. - Nuttall : p. 290 pl. 24, figs. 16-17
1957 Clavigerinella jarvisi Cushman. - Bolli : p. 272 pl. 35, figs. 5-6
Pearson et al. (2006): 1930 Hastigerinella jarvisi Cushman. - Cushman : p.18 pl. 3; fig. 8 [Eocene, Upper marl, Trinidad]
1930 Hastigerinella eocanica var. aragonensis Nuttall. - Nuttall : p.290 pl. 50; fig. 9-11 [lower Eocene, Arrayo region, Mexico]
1948 Hastigerinella eocanica Nuttall. - Stainforth : p. 116-117 pl. 26; fig. 18, 19 (detached chambers) [upper Eocene,
Ecuador]
1955 Hastigerinella eocanica Nuttall. - Weiss : p.309 pl. 2; fig. 11-13 [middle
Eocene Talara, Chira and Mirador Fms, Northern Peru];
[Not Nuttall, 1930]
non 1971 Clavigerinella jarvisi Cushman. - Postuma : p.132 pl. on p. 133 (4 specimens, right hand column) [Eocene
Globorotalia bullbrooki Zone to Globigerapsis kugleri
Zone, Navet Fm. Trinidad]; (= Clavigerinella eocanica)
2006 Clavigerinella jarvisi Cushman. - Pearson et al. : p.220 pl. 8.2; fig. 14-18 (PI. 8.2, Fig. 14: new SEMs of the holotype of
Hastigerinella jarvisi Cushman);
(Pl. 8.2, Figs. 17-18: new SEMs of the holotype of
Hastigerinella eocanica var. aragonensis Nuttall)
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| Was used in synonym list of: | ||||||
| Specimen: | ||||||
| Smithsonian Museum of Natural History, Washington, D.C., Inventory number: USNM 12565 Smithsonian Museum of Natural History, Washington, D.C., Inventory number: USNM 12566-12567 Smithsonian Museum of Natural History, Washington, D.C., Inventory number: USNM 370415 |
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| References: | ||||||
Cushman,J.A. (1930): Nuttall,W.L.F. (1930): Stainforth,R.M. (1948): Weiss,L. (1955): Bolli,H.M. (1957): Postuma,J.A. (1971): Pearson,P.N.; Olsson,R.K.; Hemleben,C.; Huber,B.T. and Berggren,W.A. (2006): |
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| Anonymous: Unedited TaxonConcept data | ||||||
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