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Species Pseudoglobigerinella bolivariana Petters 1954 | ||||||
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| Diagnosis / Definition: | ||||||
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Pearson et al. (2006): DESCRIPTION. Type of wall: Normal perforate, spinose, high porosity, reticulate, Clavigerinella-type wall structure, covered by a thick crust in adult stage. Test morphology: Test globular, nearly involute, asymmetrically planispiral in adult stage (juvenile stage very low trochospiral), slightly lobulate in outline, chambers globular; in spiral view generally 4 globular, embracing chambers in ultimate whorl, increasing rapidly in size, in terminal stage ultimate chamber overlaps the spiral coil, sutures moderately depressed, straight; in umbilical view 4-5 globular, embracing chambers, increasing rapidly in size, ultimate chamber much inflated, sutures moderately depressed, straight, umbilicus small and often covered by ultimate chamber; in edge view chambers globular in shape, slightly embracing, aperture asymmetrically equatorial, varying from a low arch to a high distinctive arch, bordered by an imperforate rim and sometimes by a narrow lip that broadens on both sides towards the center of the coil. Size: Maximum diameter of holotype 0.52 mm, thickness 0.40 mm. |
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| Discussion / Comments: | ||||||
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Pearson et al. (2006): DISTINGUISHING FEATURES. Pseudoglobigerinella bolivariana is identified by its compact, nearly involute, globular test, asymmetrical equatorial aperture, and the Clavigerinella-type reticulate wall texture and thickened crust. It is distinguished from Parasubbotina grifinae by having an aperture that extends on to the spiral side. DISCUSSION.- Pseudoglobigerinella bolivariana has long been considered an enigmatic species due to its equatorial aperture. Blow (1 979) was uncertain of its generic designation when he placed the species in 'Hastigerina?', emphasizing its homeomorphy with the Recent species 'Hastigerina siphonifera' (= Globigerinella siphonifera) which he regarded as derived from the trochospiral species Globorotalia (Turborotalia) obesa (Blow, 1979, p. 1178). He regarded his new species, Globorotalia (Turborotalia) griffinae Blow 1979, as having an analogous ancestral relationship with P bolivariana as G. obesa did with H. siphonifera (i.e., the derivation of planispiral coiling from a low trochospirally coiled morphotype). Toumarkine and Luterbacher (1 985) followed Blow in placing bolivariana in ' Hastigerina' . Blow selected the holotype and some paratypes for his new species G. (T) griffinae fiom the same sample (KANE 9 Core 42, 200 cm) from which he also illustrated bolivariana. His case for regarding griffinae as ancestral to bolivariana is clear from the SEM illustrations of the two species (his pl. 150, figs. 1-9) as they both share a Clavigerinella-type reticulate wall texture (but see comments under Paragloborotalia griflnoides regarding other paratypes of griffinae). Blow also emphasized the general range of morphologic variation in his illustrations of bolivariana (Blow, 1979, p. 1178) in morphotypes that are more loosely coiled with 5 chambers in the ultimate whorl, to the tightly coiled morphotype with a large inflated ultimate chamber. Toumarkine and Luterbacher (l 985) illustrated large inflated morphotypes (their fig. 27.25-28) similar to the holotype but also illustrated a form (their fig. 27.29) similar to the loosely coiled forms illustrated by Blow (his pl. 150, figs. 3, 4). Plate 5.14 (this chapter) shows some of the range of morphologic variation observed in this species. Of aterest is the considerable variation in the size of the aperture, from a low arch to a highly elevated arch. The derivation of the lineage leading to Pseudoglobigerinella bolivariana is uncertain, as the species has not been intensively studied in stratigraphic sections. Weiss (1955) noted the tendency in some morphotypes ofP bolivariana "towards Globigerinellalike uncoiling" (1955, p. 309) as did Toumarkine and Luterbacher (their fig. 27.29). Blow was struck by the close homeomorphy with the Recent species Hastigerina skhonifera (=Globigerinella siphonlfera) and believed that "both the Neogene and Palaeogene forms have the same basic globigerinacean wall structure" (Blow, 1979, p. 1176). However, subsequent studies show that siphonifera has a bulloides-type wall texture (Hemleben, and others, 199 1) whereas P bolivariana has a reticulate, Clavigerinella-type wall texture (this volume), much different from that ofsiyhonfera. Thus, the two species exhibit only a gross homeomorphic similarity. Although Blow placed bolivariana questionably in Hastigerina, he believed that bolivariana should be placed in a new genus if it was demonstrated that the two species could be morphologically separated. Hillebrandt (1976) considered Globigerina inaequispira Subbotina (=Parasubbotina inaequispira) as the ancestor of his new species Pseudohastigerina sphaeroidalis (here considered a junior synonym of P. bolivariana). Blow (1979, p. 749) also entertained a similar idea, in that he believed "that Globorotalia (Turborotalia) griffinae represents the derivation of an essentially turborotaliid type of coiling pattern.. .from the morphotypes included in Subbotina inaequispira", from which he derived P. bolivariana. As discussed above, there are two sets of morphotypes that Blow included in his species grfinae. The first set (illustrated on his pl. 150) appears related to bolivariana in that it possesses a high porosity reticulate Clavigerinella-type wall texture like bolivariana. This type of wall texture also occurs in Parasubbotina eoclava Coxall, Huber, and Pearson, which is regarded as the ancestral species of the Clavigerinella lineage (Coxall and others, 2003) and also in P. inaequispira, particularly in the late early Eocene (see discussion under P. inaequispira). Thus, it appears that P. inaequispira gave rise to two planispiral genera in the late early Eocene, Pseudoglobigerinella and Clavigerinella. Pseudoglobigerinella bolivariana is a rare species except in areas of high productivity, where it can dominate the planktonic foraminiferal assemblages. The species was first described by Petters (1 954) from the same sample as Clavigerinella colombiana (Petters), which is also considered by us as an indicator of high productivity. In Ecuador, Stainforth (1948) reported that bolivariana was frequently associated with radiolarianrich shales, and Weiss (1 955) recorded it in depauperate assemblages from Peru that were probably affected by upwelling. The griffinae-bolivariana-colombiana biofacies may prove of some use in delineating ancient areas of upwelling. PHYLOGENETIC RELATIONSHIPS.- Pseudoglobigerinella bolivariana was derived from Parasubbotina griffinae by a more rapid increase in chamber size, the development of a nearly involute planispiral test, and an asymmetrical equatorial aperture. GEOGRAPHIC DISTRIBUTION.- identified only in middle Eocene low latitude upwelling areas. STABLE ISOTOPIC PALEOBIOL0GY.- No data available. |
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| Systematics: | ||||||
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35 Ordo Foraminiferida Superfamilia Globigerinaceae Familia Globigerinidae Genus Pseudoglobigerinella Species Pseudoglobigerinella bolivariana |
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| Synonym list: | ||||||
| Pearson et al. (2006): ? 1948 Globigerina wilsoni Cole. - Stainforth : p.117 pl. 26; fig. 1-3 [upper Eocene?, coastal Ecuador]. [Not Cole, 1927.]
1954 Globigerina wilsoni bolivariana Petters. - Petters : p.39 pl. 8; fig. 9a-c [middle Eocene Asterigerina crassaformis Zone,
Carreto Fm., Colombia]
1955 Globigerina wilsoni bolivariana Petters. - Weiss : p.309 pl. 2; fig. 6-8 [middle Eocene, lower Talara shales, northwestern Peru]
1956 Globigerinella alexi Haque. - Haque : p.177 pl. 27; fig. 7a, b [Eocene, Pakistan]
1972 Globigerina? bolivariana pannonica Samuel. - Samuel : p. 172-173 [lower Eocene, west Carpathians,
Czechoslovakia]
1976 Pseudohastigerina globulosa Hillebrandt. - Hillebrandt : p.338 pl. 2; fig. 1a-5b [Globorotalia palmeri Zone, southern
Spain.-Subsequently renamed Pseudohastigerina
sphaeroidalis (Hillebrandt, 1978) due to secondary
homonym status of P. globulosa Hillebrandt]. [Not
Pseudohastigerina wilcoxensis globulosa Gohrbandt
1967, the
1978 Pseudohastigerina sphaerodalis Hillebrandt. - Hillebrandt : p.337 [new
name for Pseudohastigerina globulosa Hillebrandt; see
above].
1979 Hastigerina? bolivariana Petters. - Blow : p.1177 pl. 150, fig. 1-4 [lower Eocene Zone E7, KANE 9-Core 42,Endeavour Seamount, eastern North Atlantic Ocean];
pl. 251, fig. 8 [Zone E7, Langley Fm., Jamaica]
1985 "Hastigerina" bolivariana Petters. - Toumarkine & Luterbacher : p.127 fig. 27.24a-c (reillustration of holotype);
fig. 27.25-29 [early Middle Eocene, El Datil
Fm., Punta Mosquito, Venezuela]
2006 Pseudoglobigerinella bolivariana Petters. - Pearson et al. : p.98 pl. 5.14; fig. 1-22 (PI. 5.14, Figs. 1-3: new SEMs of holotype of Globigerina wilsoni bolivariana Petters)
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| Specimen: | ||||||
| Cushman Collection - Smithsonian Museum of Natural History, Washington, D.C., Inventory number: USNM 689637 |
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| References: | ||||||
Stainforth,R.M. (1948): Petters,V. (1954): Weiss,L. (1955): Haque,A.F.M.M. (1956): Samuel,O.. (1972): Hillebrandt,A. (1976): Hillebrandt,A. (1978): Blow,W.H. (1979): Toumarkine,M. and Luterbacher,H.P. (1985): 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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