Early Cretaceous planktonic foraminifera from the Tethys: the large, many-chambered representatives of the genus Globigerinelloides

Cretaceous Research 24 (2003) 661–690

Early Cretaceous planktonic foraminifera from the Tethys: the large, many-chambered representatives of the genus Globigerinelloides D. Verga*, I. Premoli Silva Dipartimento di Scienze della Terra, Universita` di Milano, Via Mangiagalli 34, I-20133, Milano, Italy Accepted 15 July 2003

Abstract This paper deals with the taxonomic revision of the Early Cretaceous large, many-chambered planispiral planktonic foraminifera, historically assigned to the genus Globigerinelloides or alternatively assigned in the 1990s to the genera Globigerinelloides Cushman and ten Dam, Biglobigerinella Lalicker, Blowiella Krechmar and Gorbachik and Alanlordella BouDagher-Fadel. In a previous paper we demonstrated that the morphological and microstructural features used in the literature for distinguishing Blowiella from Globigerinelloides have value only at species level, and the former genus was thus invalidated (being the junior synonym). Moreover, the Late Aptian specimens assigned to Biglobigerinella by some authors, based on the presence of twin last chamber(s), are also included in Globigerinelloides because individuals sharing the same features (number of chambers, growth rate, size of umbilicus, and a finely perforate wall) may or may not possess twin last chamber(s). Meanwhile, Moullade et al. questioned the taxonomic value of Alanlordella, erected by BouDagher-Fadel to accommodate planispiral taxa possessing a macroperforate wall. All the species analysed here possess a finely perforate wall and consequently cannot be assigned to this taxon. The large species of Globigerinelloides retained here, with six or more chambers in the outer whorl, are G. algerianus Cushman and ten Dam, G. aptiensis Longoria, G. barri (Bolli, Loeblich and Tappan) and G. ferreolensis (Moullade). In the sections studied, Globigerinelloides aptiensis was first found close to the Barremian/Aptian boundary, even though this species was recorded in Spain (Rio Argos) in the mid Upper Barremian; very rare, small, seven-chambered individuals here assigned to Globigerinelloides ferreolensis are recorded in the Lower Aptian (just below and within the Selli Level, OAE1a), while a few specimens belonging to Globigerinelloides barri occur in the Globigerinelloides ferreolensis Zone (Upper Aptian). Globigerinelloides aptiensis and G. ferreolensis range up to the Ticinella bejaouaensis Zone while Globigerinelloides barri disappears at the top of the Globigerinelloides algerianus Zone; finally, Globigerinelloides algerianus obviously spans the eponymous total range zone. From an evolutionary point of view, two lineages within the many-chambered Globigerinelloides have been recognized. In the first, already known in the literature, Globigerinelloides aptiensis gave rise to G. ferreolensis, which evolved into G. algerianus; the latter in turn gave rise to Pseudoplanomalina cheniourensis as the final evolutionary member. In the second lineage Globigerinelloides barri originated from G. blowi.  2003 Elsevier Ltd. All rights reserved. Keywords: planktonic foraminifera; Globigerinelloides; Biglobigerinella; Blowiella; Upper Aptian; Upper Barremian; Selli Level; OAE1a; Italy; SE France; offshore Morocco

1. Introduction This paper deals with the taxonomic revision of the large, six or more-chambered, planispiral species * Corresponding author: Tel: +39 02 50315528; Fax: +39 02 50315494 E-mail address: [email protected] (D. Verga). 0195-6671/03/$ - see front matter  2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.cretres.2003.07.007

of Early Cretaceous age, originally described and/or included in the genus Globigerinelloides and more recently alternatively assigned to the genera Alanlordella, Biglobigerinella, Blowiella, and/or retained in the genus Globigerinelloides (Krechmar and Gorbachik, 1971; Banner and Desai, 1988; BouDagher-Fadel, 1995; BouDagher-Fadel et al., 1997; Moullade et al., 2002). In this paper we aim to (1) clarify the possible similarities

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or differences between these four genera, and (2) highlight the morphological features of each taxon by exhaustive taxonomic descriptions at the species level. Globigerinelloides was erected in 1948 by Cushman and ten Dam, with G. algerianus sp. nov. as type species, for the Cretaceous planispiral, non-keeled forms previously attributed to Cenozoic taxa. With the advent of the Scanning Electronic Microscope (SEM) in the late 1960s–early 1970s, the study of planktonic foraminifera, including this planispiral group, began routinely to involve observations of microstructural wall features. As a consequence, many of the genera previously described and identified on the basis of morphological characters visible at the stereomicroscope were split to several new taxa at both generic and specific levels. The first authors to apply microstructural wall features as a taxonomic criterion at generic level were Krechmar and Gorbachik (1971). They erected the new genus Blowiella to accommodate the small planispiral forms previously included in Globigerinelloides, claiming that Blowiella possesses a thin monolamellar wall instead of a thick, bilamellar wall like Globigerinelloides. Longoria (1974) did not consider Blowiella to be valid; according to him (p. 76), Krechmar and Gorbachik’s diagnostic characters of Blowiella ‘fall within the morphological variation allowable for the genus Globigerinelloides’. Moreover, he regarded (p. 77) the genus Biglobigerinella Lalicker 1948 (type species B. multispina sp. nov.), previously accepted by Loeblich and Tappan (1964), as an artificial genus (a synonym of Globigerinelloides) because he considered the presence of final paired chambers as a specific character of gerontic individuals. Loeblich and Tappan (1987) considered both Biglobigerinella and Blowiella to be valid taxa; however, in the description of the latter they stated that Blowiella differs from Globigerinelloides in having simple globular and rapidly enlarging chambers, few chambers per whorl, and poorly developed relict apertures, assuming that the wall in Blowiella was multilamellar as in the other planktonic foraminifera. In the same year, Banner and Desai (1988) further emended Blowiella and considered pore size as the diagnostic character for distinguishing it from Globigerinelloides (small versus larger, respectively), without mentioning the fewer chambers as diagnostic for the genus. Concerning wall structure, Banner and Desai (1988) stated that Blowiella does not differ from all the other planktonic species, being bilamellar and ‘non-muricate’, implying that Globigerinelloides may possess a ‘muricate’ wall. BouDagher-Fadel (1995), following the emended diagnosis of Blowiella by Banner and Desai (1988; see above), further subdivided the planispiral plexus by erecting Alanlordella (type species Alanlordella banneri sp. nov.) for planispiral morphotypes possessing a macroperforate wall. BouDagher-Fadel et al. (1997)

erected another new genus, Claviblowiella, for the microperforate, ‘non-muricate’, planispiral taxa with elongate chambers. Therefore, the original Early Cretaceous planispiral plexus has been subdivided into four different genera; moreover, BouDagher-Fadel (1995) and BouDagher-Fadel et al. (1997) included some species attributed to Globigerinelloides in Biglobigerinella Lalicker, 1948 on account of the presence of one or two final paired chambers, further expanding the Early Cretaceous planispiral generic spectrum. Recently, Moullade et al. (2002) stated that both Blowiella and Globigerinelloides possess a microperforate wall and highlighted the poor taxonomic value of the morphological features reported by BouDagher-Fadel et al. (1997) in retaining Blowiella as a valid distinct taxon. Nevertheless, Moullade et al. (2002) still distinguished Blowiella from Globigerinelloides on the basis of the occurrence of perforation cones on the earliest outer chambers of the latter taxon. Moreover, these authors rejected Biglobigerinella and Claviblowiella, affirming that the presence of both paired and elongate chambers respectively cannot be applied in discriminating at genus level. Finally, Verga and Premoli Silva (2003) demonstrated that there are no reliable morphological and microstructural features for differentiating Blowiella from Globigerinelloides, and, consequently, Blowiella, being the junior synonym, was invalidated.

2. Material and methods The study material is mainly the same as that used for the revision of the leupoldinids (Verga and Premoli Silva 2002) and small globigerinelloidids (Verga and Premoli Silva (2003)), and consists of over 300 samples from the Cismon core (Venetian Alps, NE Italy; Fig. 1), the Calabianca section (NW Sicily; Fig. 2), the Lesches en Diois section (SE France; Fig. 3), and the Upper Aptian of Deep Sea Drilling Project (DSDP) Site 545 drilled off Morocco (Hinz, Winterer et al., 1984; Fig. 4). Samples from softer layers (shales and marls) of the sections mentioned above and DSDP Site 545 were soaked in hydrogen peroxide for few hours, then washed and sieved through >140 µm, >104 µm and >40 µm meshes (see Verga and Premoli Silva (2003)). DSDP Site 545 sediments yielded a rich, well-preserved planktonic foraminiferal assemblages that allowed the microstructural features of the original calcitic wall of the planispiral group, among other groups, to be investigated (Leckie, 1984). The relative abundance of each species with respect to the total assemblage was plotted on range charts and expressed by frequency classes (per sample) as follows: 1 specimen, very rare (vr); 2–3 specimens, rare (r); 4–5 specimens, rare to few (r/f); 6–8 specimens, few (f); 9–12

D. Verga, I. Premoli Silva / Cretaceous Research 24 (2003) 661–690

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specimens, few to common (f/c); 13–16 specimens, common (c); 17–20 specimens, common to abundant (c/a); 21–25 specimens, abundant (a); >25 specimens, very abundant (va).

The stratigraphic range of the large, six or morechambered, planispiral morphotypes was also reconstructed. Their stratigraphic distribution both in the Calabianca section and in the Cismon core is calibrated

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to the nannofossil zonation and in the latter is also calibrated to the magnetostratigraphic scale (Erba et al., 1999). The planktonic foraminiferal zonation scheme used here is based mainly on the schemes of Longoria (1974), Caron (1985) and Robaszynski and Caron (1995), as modified by Premoli Silva and Sliter (1999). 3. Geological settings The location, geological setting and main lithologies of the Cismon core (Fig. 1), the Calabianca section (Fig. 2), and the Lesches en Diois section (Fig. 3) were reported by Verga and Premoli Silva (2002), to which reference should be made for detailed descriptions. DSDP Site 545 (Fig. 4), drilled off Morocco (water depth 3150 m), penetrated 701 m of sediments comprising four lithologic units (Units I–IV) ranging in age from possibly Middle Jurassic to Holocene (Hinz, Winterer et al., 1984). The 45 samples studied from the site belong to the lowermost part of Subunit IIIA and the whole of Subunit IIIB of Unit III (406.5–531 mbsf, Cores 44–56), which are mainly composed of greenish grey nannofossil claystone with subordinate clayey nannofossil chalks that have been attributed to the Upper Aptian, from the base of the Globigerinelloides ferreolensis Zone to the lower part of the Ticinella bejaouaensis Zone (Leckie, 1984). 4. Globigerinelloides versus Blowiella, Biglobigerinella and Alanlordella Because of the taxonomic complexity resulting from the proliferation of genera within the planispiral plexus (see above), the thinking of previous authors concerning the genera Globigerinelloides, Blowiella, Biglobigerinella

and Alanlordella is summarized along with our critical comments in Table 1. The limited taxonomic value of Blowiella was discussed in Verga and Premoli Silva (2003). We unequivocally showed that the microstructural features and morphological characteristics used by previous authors (see above) in considering Blowiella as a valid genus can be applied only at species level. Therefore, we concluded that Blowiella is a junior synonym of Globigerinelloides, and consequently re-assigned all the species temporarily included in Blowiella to Globigerinelloides. Concerning Biglobigerinella, we agree with previous authors (e.g. Berggren, 1962; Pessagno, 1967; Longoria, 1974, and Moullade et al., 2002) that the paired last chamber(s) present in some Biglobigerinella specimens must be considered a peculiarity developed only by gerontic individuals and thus cannot be considered as a valid feature at genus level. Although Bolli et al. (1957) erected the new species barri, attributing it to the genus Biglobigerinella by the presence of one or more paired final chambers, in our material we found several specimens positively attributable to the same species that lack paired last chambers. Should we then include barri morphotypes without twin final chambers in a different genus, that is in Globigerinelloides, and the others with paired last chambers in Biglobigerinella, even though there are no other features separating them? Being against this hypothesis, we include the morphotypes with or without twin final chambers in the species barri, including this in the genus Globigerinelloides. On the other hand, the type species Biglobigerinella multispina was described by Lalicker (1948) from the Campanian–Maastrichtian, so Biglobigerinella may be valid if it can be proved that morphotypes lacking paired last chambers, but similar in the other features, do not co-occur with the true B. multispina, and its wall is

D. Verga, I. Premoli Silva / Cretaceous Research 24 (2003) 661–690

positively shown to be different from that of the Aptian forms. The taxonomic problems related to Alanlordella and Claviblowiella will be treated in further studies.

5. Taxonomic value of ‘perforation cones’ in the planispiral plexus It is undeniable that the early chambers of the outer whorl in the many-chambered, large representatives of the Aptian planispiral plexus exhibit a smooth to more or less rough surface. Close observation of the wall in several well-preserved planispiral individuals from the Lesches en Diois section and DSDP Site 545 has allowed better definition of the nature of this microstructural feature. A rough surface in the early chambers of the last whorl first occurs in rare specimens belonging to Globigerinelloides aptiensis (correct spelling for G. aptiense Longoria; see BouDagher-Fadel et al., 1997) and becomes much more frequent in all the other Globigerinelloides taxa (G. algerianus, G. barri and G. ferreolensis). Rugosities are usually randomly distributed and appear as stout pustules (muricae auctorum?) that may fuse to make features like ridges or plates without exhibiting well-defined patterns. On these rough surfaces pores are visible only occasionally in between rugosities (Fig. 5). BouDagher-Fadel (1995), in describing the microstructural features of type material of Globigerinelloides algerianus and G. ferreolensis, stated (p. 139) that Globigerinelloides ‘is microperforate and non-muricate in the last whorl (although it commonly develops ‘perforation cones’ on the periphery of the earliest chamber of the last whorl)’. Again, Moullade et al. (2002) discriminated between Blowiella and Globigerinelloides on the basis of the occurrence of ‘perforation cones’ on the earliest outer chambers of the latter genus. ‘Perforation cones’, volcano-like structures, were first described by Banner et al. (1993) as occurring in the early chambers of the outer whorl of some trochospiral individuals belonging to Praehedbergella and Blefuscuiana, and their presence/absence was applied at subspecies level. According to our observations, in the trochospiral group ‘perforation cones’ may cover the surface of the earliest chambers entirely and regularly, always possessing pores at the top. On the other hand, the rugosities observed on early outer chambers of Globigerinelloides are randomly distributed, irregular in shape and thickness, and devoid of pores, and cannot then be equated to the true ‘perforation cones’ of the trochospiral group, being simply pustules. For that reason the occurrence of rugosity in the planispiral plexus cannot be applied in discriminating at genus level. Moreover, this feature is not consistently applied in the literature. For instance, BouDagher-Fadel

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et al. (1997) reported as an additional character of Globigerinelloides the possible presence of ‘perforation cones’ on the early outer chambers (without any taxonomic discrimination between smooth and pustulose individuals); they also considered ‘perforation cones’ at subspecies rank in the trochospiral plexus. Moullade et al. (2002), p. 114) stated that BouDagher-Fadel et al. (1997) applied the taxonomic use of ‘perforation cones’ in an ambiguous way, writing ‘this criterion, considered to be only of infra-specific rank in trochospiral forms . . . is upgraded to generic rank for the planispiral forms’. Paradoxically, Moullade et al. (2002) still maintained Blowiella distinct from Globigerinelloides on the basis of its smooth wall (lacking ‘perforation cones’), and, conversely, included in the same species (Praehedbergella infracretacea) individuals both with and without ‘perforation cones’. The appearance of a rough surface in the early chambers of the outer whorl of large globigerinelloidids might be either an evolutionary feature or related to the ontogenetic stage of the individuals (largest specimens possess numerous lamellae which could accentuate the roughness of the surface). However, the possibility that the presence/absence of rough surfaces could be simply related to preservation, overgrowth or recrystallization factors cannot be ruled out. On the basis of our observations, no taxonomic value can be attributed to the surface features described above; consequently, we agree with BouDagher-Fadel (1995) and BouDagher-Fadel et al. (1997) in lumping smooth and rough planispiral morphotypes under the same species. In conclusion, it is worth mentioning that in most cases surface features are only recognizable through SEM observation, especially on small specimens, making them of little practical use. 6. Previous observations at species level The confused taxonomic organization of the Early Cretaceous planispiral plexus obviously also affected the taxonomy at species level. For many years the morphological features proper of each species were frequently misinterpreted in addition to the proliferation of several new taxa, often of uncertain taxonomic value. The original taxonomic annotations of previous authors concerning the Early Cretaceous, large planispiral species, together with our critical comments, are schematically reported in Table 2. Concerning Globigerinelloides algerianus and G. ferreolensis, we agree with BouDagher-Fadel et al. (1997) and Moullade et al. (2002) that these two species possess a finely perforate, frequently rugose wall, and that by definition they belong to Globigerinelloides. As noted in Table 2, the finely perforate wall, mainly with a rough texture, was also observed in the species barri (=Biglobigerinella barri Bolli et al., 1957) as already noted by Moullade et al. (2002). On the basis of this

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Table 1 Taxonomic annotations on previous literature concerning the Early Cretaceous planispiral plexus. Author(s)

Original annotations

1948

Cushman and ten Dam

1948

Lalicker

1971

Krechmar and Gorbachik

Erected the genus Globigerinelloides (type species Globigerinelloides algerianus sp. nov.) to accommodate the Early Cretaceous, non-keeled, planispiral specimens with relict apertures; they described the wall as finely perforate and somewhat pustulose. Formalized the genus Biglobigerinella from Campanian–Maastrichtian strata) for accommodating the non-keeled, planispiral individuals with relict apertures and last paired chamber(s); type species Biglobigerinella multispina. Distinguished the new genus Blowiella from Globigerinelloides by the thinness of the wall in the former; they claimed that Blowiella possesses a thin, monolamellar wall instead of the thick multilamellar wall like Globigerinelloides. Affirmed that Blowiella can be recognized from Globigerinelloides by possessing a more or less involute test. Emended the genus Globigerinelloides on the basis of a more accurate description of the features of the primary and relict apertures Stated (p. 176) that ‘the diagnosis of Blowiella (Globigerinelloides with more or less involute test) of Krechmar and Gorbachik (1971) falls within the morphologic variability allowable for the genus Globigerinelloides by the present author’. Affirmed (p. 77) that ‘as noted by Berggren (1962) and later by Pessagno (1967), Biglobigerinella Lalicker is an artificial genus. The presence of final paired chambers is here regarded as a specific characteristic displayed by ephebic individual of certain Globigerinelloides species’. Concerning the genus Blowiella, highlighted (p. 170) ‘the impracticability of depending upon high quality thin sections of wall structure before one can attempt generic diagnoses’. Claimed (p. 170) that ‘it is probable that all the taxa of Globigerinina develop lamellate walls during growth and that all possess bilamellar septa even though the inner lamella may be extremely thin’. Affirmed that Blowiella differs from the former genera Biglobigerinella and Globigerinelloides in having a microperforate non-muricate wall and, consequently, consider Blowiella as a valid genus.

1974

1988

1995

Longoria

Banner and Desai

BouDagher-Fadel

Comments

No information about the size of the pores.

Disagree; as correctly reported by Banner and Desai (1988), no difference in wall thickness can be recognized between Blowiella and Globigerinelloides.

Disagree; this feature cannot be applied at genus level as pointed out by Longoria (1974, see below).

Agree; thus, in our opinion, Blowiella is a junior synonym of Globigerinelloides.

Agree

Agree

Agree.

Disagree; the type species Globigerinelloides, G. algerianus, clearly displays a finely perforate wall, even though roughness and irregularities may possibly be present in the first chambers of the outer whorl. Moreover, we agree with Berggren (1962), Pessagno (1967), and Longoria (1974) in considering Biglobigerinella an artificial genus. Claimed (p. 139) that the ‘paratype of G. algerianus and the topotype of Agree. G. ferreolensis, as figured by Moullade (1961), show that this genus is also microperforate and non-muricate in last whorl’.

D. Verga, I. Premoli Silva / Cretaceous Research 24 (2003) 661–690

Year

Table 1 Year

2002

2003

Author(s)

BouDagher-Fadel et al.

Moullade et al.

Verga and Premoli Silva

Original annotations

Comments

Also stated (p. 139) that ‘Globigerinelloides may commonly develops perforation cones on the periphery of the earliest chambers of the last whorl’. Despite this statement, persisted in treating Blowiella and Globigerinelloides as two distinct genera affirming that the latter possesses (1) more numerous chambers, (2) more developed portici, (3) a wider umbilical area, and (4) a laterally compressed test.

Disagree; the early chambers of the species mentioned may exhibit pustules that can coalesce, resulting in ridges or plates. Moreover, these microstructures never reveal pores at their top, as observed in true perforation cones. Disagree; all the supposed morphological differences described are obviously related to the increase in the number of chambers (see Moullade et al., 2002, pp. 113–114). In addition, according to us, these features cannot be applied at genus level; moreover, laterally compressed tests are also present in the small Globigerinelloides (e.g. G. maridalensis). To be verified; this genus will be treated in a further study.

Erected the new genus Alanlordella for accommodating the macroperforate, planispiral taxa; this genus comprises two species Alanlordella banneri and A. praebuxtorfi. On the basis of the same morphological features reported in 1995, persist in treating Blowiella as a valid genus. Still reported Biglobigerinella Lalicker, 1948 as a valid, discrete genus. Established the new genus Claviblowiella to include the microperforate, non-muricate, planispiral taxa with elongate chambers. Affirmed that both Blowiella and Globigerinelloides possess a microperforate wall. Highlighted that the morphological features (i.e. the number of chambers in the outer whorl, the width of the umbilical area, the length of the ‘portici’ and the lateral compression of the test) reported by BouDagher-Fadel et al. (1997) in distinguishing Blowiella and Globigerinelloides are (1) of species rather than generic rank and (2) evolved in parallel and resulted from the same cause, i.e. the increasing number of chambers in the last whorl. Persisted in treating Blowiella and Globigerinelloides as two distinct genera on the basis of the presence of perforation cones in the latter.

Claimed that only Globigerinelloides may develop one or more paired final chambers. Considered (p. 115) the presence of one or more final twin chambers characterizing the genus Biglobigerinella as an ‘ontogenic accident affecting a few gerontic specimens . . . and thus devoid of any, at least generic taxonomic significance’. Highlighted the poor taxonomic value of the morphological features reported by BouDagher-Fadel et al. (1997) and Moullade et al. (2002) in considering Blowiella as a valid genus and consequently considered it as a junior synonym of Globigerinelloides.

Disagree (see above). Disagree (see above). To be verified; this genus will be treated in a further study. Agree. Agree.

Disagree; Globigerinelloides does not possess perforation cones; early chambers of the outer whorl simply exhibit pustules that may coalesce giving rise to ridges or plates. Again, ‘smooth’ morphotypes are also known in Globigerinelloides (see Verga and Premoli Silva, 2003). Disagree; even five-chambered planispiral individuals may exhibit this feature (see Verga and Premoli Silva, 2003). Agree

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1997

(continued)

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1

2

3

4

5

Fig. 5. Comparison between several finely perforate, Upper Aptian wall textures. 1, smooth surface of Globigerinelloides blowi. 2–4, pustules of Globigerinelloides barri. 5, perforation cones from the trochospiral group (Praehedbergella-Blefuscuiana). Scale bar=10 µm.

observation and the lack of taxonomic significance of the presence/absence of last paired chambers (see section 4 above), the Late Aptian morphotypes, previously attributed to Biglobigerinella barri, are also included in Globigerinelloides. However, in disagreement with Moullade et al. (2002), we consider Globigerinelloides barri to be a discrete taxon that differs from all the other Late Aptian planispiral taxa on account of its strongly reniform chambers resulting in a deeper umbilical area compared to that of Globigerinelloides ferreolensis and/or G. algerianus. The subdivision of the planispiral plexus into two discrete genera reported by some authors (e.g. Krechmar and Gorbachik, 1986; Banner and Desai, 1988; BouDagher-Fadel, 1995; BouDagher-Fadel et al., 1997; Moullade et al., 2002) resulted in a problematic attribution at species level of the six- to seven-chambered morphotypes. On the basis of our observations, it is possible to recognize: (1) rare individuals displaying six chambers associated with morphological features (such as growth rate and general shape) that recall the features of the small, few-chambered globigerinelloidids (Globigerinelloides blowi and G. paragottisi; see Verga and Premoli Silva 2003); and (2) other, even rarer, specimens which can be interpreted as juveniles of G. barri (i.e. the individual figured by Longoria, 1974, pl. 4, fig. 7) or of G. ferreolensis, while the only consistent morphology within the 6–6.5 chambered group coincides with the diagnosis of G. aptiensis Longoria, 1974, characterized by a finely perforate wall. Finally, the morphological characters proper of Blowiella solida Krechmar and Gorbachik (in Gorbachik, 1986) appear too weak to differentiate this species from G. aptiensis (see individuals illustrated in Longoria, 1974, pl. 8, figs. 4, 6, 17–18). Consequently, B. solida is here considered a junior synonym of the latter. 7. Key to the large representatives of the genus Globigerinelloides From the discussion above of the Upper Barremian– Upper Aptian large planispiral plexus, the species

retained here are Globigerinelloides algerianus Cushman and ten Dam, 1948, G. aptiensis Longoria, 1974, G. barri (Bolli et al., 1957) and G. ferreolensis (Moullade, 1961) (see Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10). A schematic species key to the large species of Globigerinelloides is provided in Table 3.

8. Stratigraphic distribution and evolutionary trend In the Cismon core many-chambered globigerinelloidids are in general unevenly distributed and vary greatly in abundance from layer to layer (see Table 4, Fig. 11). They first appear close to the Barremian/Aptian boundary as very small (<100 µm) specimens belonging to Globigerinelloides aptiensis followed by very rare, unevenly distributed, small, seven-chambered juveniles of G. ferreolensis. Below the Selli Level, which is equated to Oceanic Anoxic Event 1a (OAE1a; Erba et al., 1999), many-chambered globigerinelloidids are scarce in the marly and shaly beds, while they are usually more numerous in the radiolarian levels. Within the Selli Level, many-chambered globigerinelloidids are again few to absent in the marlstone, shale and limestone beds, while they are more common in the radiolarian levels; in particular, the Selli Level is characterized by a very uneven distribution of the globigerinelloidids, ranging from scarce in a few discrete intervals characterized by more diversified assemblages, to totally absent in several layers dominated by leupoldinids and clavate forms. The absence or scarcity of globigerinelloidids in some beds may be related to palaeoenvironmental factors (Premoli Silva et al., 1999), although dissolution effects cannot be ruled out. Finally, within the Selli interval the many-chambered Globigerinelloides are still small (<100 µm) and well preserved only in the radiolarian levels. Immediately above the Selli Level, the globigerinelloidids become much more abundant, larger (>300 µm) and more consistently present along with a richer planktonic foraminiferal assemblage, suggesting improved environmental conditions; however, well-preserved

Table 2 Taxonomic annotations on the previous literature concerning the species here included in the genus Globigerinelloides with relevant comments. Year

Author(s)

Globigerinelloides algerianus 1948 Cushman and ten Dam

Longoria

1988 1995

Banner and Desai BouDagher-Fadel

1997

BouDagher-Fadel

Globigerinelloides aptiensis 1959 Bolli

1974

1986

Longoria

Krechmar and Gorbachik

Comments

Instituted the species Globigerinelloides algerianus from the Upper Aptian of Algeria. The holotype exhibits a planispiral, evolute coiling mode, test subcircular and laterally compressed, twelve chambers in the outer whorl increasing fairly rapidly but gradually in size, sutures radial, depressed and slightly curved, aperture as an equatorial low arch bordered by a marked lip; wall finely perforate, somewhat pustolose. Reported the species algerianus as belonging to the genus Globigerinelloides. Described Globigerinelloides algerianus as macroperforate. Highlighted the fact that the paratype of Globigerinelloides algerianus possesses a microperforate wall. Again, assigned the species algerianus to the microperforate genus Globigerinelloides.

No information on the size of the pores.

Described as Planomalina escheri (Kaufmann) some planispiral, six-chambered individuals from Upper Aptian sediments of Trinidad.

In our opinion Bolli’s individuals do not correspond to the original diagnosis of Planomalina escheri Kaufmann. Conversely, they perfectly correspond to the type material of Globigerinelloides aptiensis Longoria, 1974 and for this reason are included in the synonymy of G. aptiensis.

Formalized the new species Globigerinelloides aptiensis from the Upper Aptian of SE France. Described this taxon as planispiral, evolute and lobate; 5–6 spherical chambers in the outer whorl; chambers increasing gradually in size; sutures depressed and radial, umbilical area wide. Affirmed that five-chambered specimens are much less frequent than six-chambered ones (three individuals out of 25 specimens of G. aptiensis found). Established the new species Blowiella solida from the Upper Aptian of Crimea. Described this taxon as possessing 6–7 outer chambers.

Agree. Disagree (see below). Agree. Agree.

No information concerning the size of the pores or wall surface.

Agree; all the individuals illustrated by Longoria (1974) possess six chambers in the outer whorl. The poorly illustrated (a single umbilical, tilted view) holotype of this species exhibits 6.5 slowly enlarging chambers resulting in a moderately lobate, hexagonal test. Blowiella solida falls, in our opinion, in the morphological variability of Globigerinelloides aptiensis Longoria, 1974; it differs from the holotype of the latter taxon only in possessing a slightly less lobate peripheral outline and 6.5 (instead of six) chambers in the outer whorl. These differences are too weak in differentiating these two species and, moreover, the general morphology shown by the holotype of Blowiella solida is very close to that of Globigerinelloides aptiensis illustrated by Longoria (1974, pl. 8, figs. 4–6, 17–18).

D. Verga, I. Premoli Silva / Cretaceous Research 24 (2003) 661–690

1974

Original annotations

669

670

Table 2

(continued) Author(s)

Original annotations

Comments

1997

BouDagher-Fadel et al.

Still reported Blowiella solida affirming that this taxon possesses 5–6 chambers in the outer whorl.

According to Moullade et al. (2002) these authors re-figured (pl. 10.2, fig. 4) the holotype of this species (erroneously reported as the topotype). Again, this poor illustration (a single umbilical, tilted view) does not clarify our doubts about this taxon; they also illustrated (pl. 102, figs. 5–6), a five-chambered specimen (lacking the edge view); this individual does not correspond to the original diagnosis (with 6–7 chambers) of Krechmar and Gorbachik (1986). Moreover it exhibits a much faster growth rate and, in our opinion, falls within the morphological variability of Globigerinelloides paragottisi Verga and Premoli Silva (2003). The only individual illustrated by BouDagher-Fadel et al. (1997) is the holotype reported by Longoria (1974). No close-up image of the dimension of the pores was provided in support of this hypothesis. A close analysis of the poorly preserved holotype of Globigerinelloides aptiensis (B. Huber, pers. comm., 2001) shows that this taxon does not possess macroperforations. In addition, all the six-chambered taxa corresponding to the Longoria’s diagnosis found in our study clearly exhibit a microperforate wall. In our opinion this specimen falls in the morphological variability of Globigerinelloides aptiensis. Agree (see above).

Claimed that Globigerinelloides aptiensis Longoria, 1974 possesses a macroperforate, muricate wall and consequently named this taxon Alanlordella aptiensis.

1998

Moullade et al.

2002

Moullade et al.

Illustrated in their pl. 5, fig. 9 as Blowiella sp. an individual with six, slowly enlarging chambers. Highlighted that Globigerinelloides aptiensis Longoria, 1974 possesses a microperforate wall. Described Globigerinelloides aptiensis as pseudoplanispiral.

Still reported Blowiella solida. Globigerinelloides barri 1957 Bolli et al.

1974

Longoria

1997

BouDagher-Fadel et al.

Formalized the new species Biglobigerinella barri from the Upper Aptian of Trinidad.

Disagree; Globigerinelloides aptiensis is planispiral as supported by the symmetrical position of the primary aperture of the type material and of the individuals illustrated here. Disagree; in our opinion Blowiella solida is a junior synonym of Globigerinelloides aptiensis (see above).

No information on the size of the pores or on wall surface; however, a close analysis of the holotype of Biglobigerinella barri (B. Huber, pers. comm., 2001) shows that this taxon does not possess a macroperforate wall. Assigned Biglobigerinella barri to the genus Globigerinelloides, Agree; besides the bilobation of the last chambers, this taxon possesses distinct highlighting the poor taxonomic value of the last paired chamber(s) morphological features (e.g. reniform chambers in edge view and a deep displayed only by some gerontic (his ‘ephebic’) individuals of this umbilical area) that allow it to be clearly distinguished from other Upper species. Aptian planispiral species. Illustrated (in pl. 4, fig. 7) as Globigerinelloides blowi, an individual with This specimen does not correspond to the original diagnosis of this species (5–6 seven reniform chambers and a deep umbilical area. chambers in the last whorl); its general morphology allows it to be considered as a juvenile Globigerinelloides barri. Described Biglobigerinella barri as macroperforate. Illustrated the Disagree (see above). holotype of Bolli et al. (1959) showing twin last chambers and one specimen of Longoria (1974) without this feature.

D. Verga, I. Premoli Silva / Cretaceous Research 24 (2003) 661–690

Year

Table 2

(continued) Author(s)

Original annotations

Comments

1998

Moullade et al.

2002

Moullade et al.

Illustrated as G. ferreolensis (pl. 5, figs. 1, 4–6) specimens with reniform, even bilobate, chambers. Included the species barri in the microperforate genus Globigerinelloides. Rejected the taxonomic value of the lateral widening of the chambers reported in the literature as a distinctive feature of this species; assigned to Globigerinelloides barri only the individuals with nine chambers (like the holotype). Noted that final paired chambers have never been observed in the small planispiral plexus. Considered this species to be an intermediate between G. ferreolensis and G. algerianus.

These specimens, in our opinion, fall in the variability of Globigerinelloides barri. Agree (see above). Disagree; Globigerinelloides barri possesses distinct morphological features that allow it to be easily recognized from all other Upper Aptian planispiral forms (see above); in addition, it has been described, in the literature, as possessing 8–10 chambers in the last whorl. Disagree; Globigerinelloides blowi displays this feature (see Verga and Premoli Silva, (2003) Disagree; in our opinion Globigerinelloides barri evolved from G. blowi as supported by the attitude of both taxa in developing reniform chambers in edge view, the last one or two possibly bilobate (see text and Verga and Premoli Silva, (2003)

2003

Verga and Premoli Silva

Globigerinelloides ferreolensis 1961 Moullade

1966 1974

Moullade Longoria

1988 1995

Banner and Desai BouDagher-Fadel

1997

BouDagher-Fadel et al.

2002

Moullade et al.

Demonstrated that Globigerinelloides blowi may also develop one or more final paired chambers. First described this species as Biticinella ferreolensis from the Upper Aptian of southern France. The holotype exhibits planispiral, evolute coiling mode, test ovoid and laterally inflated, eight chambers in the outer whorl incr4easing rather fast but gradually in size, sutures radial, depressed and slightly curved, aperture as an equatorial low arch. Included the species ferreolensis in Globigerinelloides. Instituted the species Globigerinelloides macrocameratus from Upper Aptian sediments of France and Mexico; he affirmed that this taxon differs from Globigerinelloides ferreolensis in having a markedly wider last chamber. Described Globigerinelloides ferreolensis as macroperforate. Highlighted the fact that a topotype of Globigerinelloides ferreolensis possesses a smooth, microperforate wall. Again, assigned the species ferreolensis to the microperforate genus Globigerinelloides. Reported Globigerinelloides macrocameratus Longoria, 1974 as a junior synonym of G. ferreolensis. Reported Globigerinelloides macrocameratus Longoria, 1974 as a junior synonym of G. ferreolensis.

No information about the wall features.

Agree. Disagree; in our opinion Globigerinelloides macrocameratus falls within the morphological variability of G. ferreolensis.

Disagree (see below). Agree. Agree.

D. Verga, I. Premoli Silva / Cretaceous Research 24 (2003) 661–690

Year

Agree. Agree.

671

672

D. Verga, I. Premoli Silva / Cretaceous Research 24 (2003) 661–690

1a

4a

6a

8a

10a

1b

4b

2a

4c

5a

7a

6c

6b

8b

10b

2b

8c

9a

11a

11b

3a

5b

3b

5c

7c

7b

9c

9b

12a

12b

Fig. 6. 1-11, Globigerinelloides aptiensis. 1a–b, Lesches en Diois L8. 2a–b, Lesches en Diois L8. 3a–b, Lesches en Diois L8. 4a–c, DSDP Leg 79-545-55-5, 4 cm. 5a–c, Lesches en Diois L10. 6a–c, Lesches en Diois L10. 7a–c, Lesches en Diois L9. 8a–c, Lesches en Diois L5. 9a–c, Lesches en Diois L8. 10a–b, Lesches en Diois L10. 11a–b, Cismon 13/13-17. 12a–c, Globigerinelloides aptiensis trans. ferreolensis, DSDP Leg 79-545-55-5, 4 cm. Scale bars represent 200 µm in 1a–b–3a–b, 5a–b–10a–b; 100 µm in 4a–b, 11a–b, 12a–b; 10 µm in 4c–9c.

D. Verga, I. Premoli Silva / Cretaceous Research 24 (2003) 661–690

1a

3a

5a

7a

11a

1b

3b

5b

7b

11b

1c

2a

3c

4a

5c

8a

11c

2b

4b

6a

8a

6b

9a

12a

673

9b

12b

2c

4c

6c

10a

10b

12c

Fig. 7. 1–3, Globigerinelloides aptiensis trans. ferreolensis. 1a–c, DSDP Leg 79-545-55-5, 4 cm. 2a–c, Lesches en Diois L9. 3a–c, DSDP Leg 79-545-55-CC, 7 cm. 4–12, Globigerinelloides ferreolensis. 4a–c, Lesches en Diois L10. 5a–c, Lesches en Diois L9. 6a–c, Lesches en Diois L10. 7a–b, Lesches en Diois L9. 8a–b, Lesches en Diois L8. 9a–b, DSDP Leg 79-545-55-5, 4 cm. 10a–b, DSDP Leg 79-545-55-5, 4 cm. 11a–c, Lesches en Diois L10. 12a–c, Lesches en Diois L9. Scale bars represent 200 µm in 2a–b–5a–b, 12a–b; 100 µm in 1a–b, 6a–b–11a–b; 10 µm in 1c–6c, 11c, 12c.

674

D. Verga, I. Premoli Silva / Cretaceous Research 24 (2003) 661–690

1a

5a

7a

9a

11a

1b

2a

5b

7b

9b

11b

5c

7c

9c

11c

2b

3a

6a

8a

10a

12a

3b

6b

8b

10b

12b

4a

4b

6c

8c

10c

12c

Fig. 8. 1–8, Globigerinelloides ferreolensis. 1a–b, Lesches en Diois L10. 2a–b, Lesches en Diois L10. 3a–b, Lesches en Diois L10. 4a–b, Lesches en Diois L9. 5a–c, Lesches en Diois L9. 6a–c, Lesches en Diois L9. 7a–c, Lesches en Diois L9. 8a–c, DSDP Leg 79-545-55–5, 4 cm. 9–12, Globigerinelloides algerianus. 9a–c DSDP Leg 79-545-55-5, 4 cm. 10a–c, DSDP Leg 79-545-55-5, 4 cm. 11a–c, DSDP Leg 79-545-55-CC, 7 cm. 12a–c, DSDP Leg 79-545-55-5, 4 cm. Scale bars represent 200 µm in 2a–b, 4a–b 9a–b–12a–b; 100 µm in 1a–b, 4a–b–8a–b; 10 µm in 5c–12c.

D. Verga, I. Premoli Silva / Cretaceous Research 24 (2003) 661–690

1a

1b

1c

3a

3b

3c

5a

5b

5c

7a

11a

7b

11b

2a

4a

8b

12b

4c

6c

6b

9a

13a

2c

4b

6a

8a

12a

2b

9b

13b

675

10a

14a

10b

14b

Fig. 9. 1–13, Globigerinelloides algerianus. 1a–c, DSDP Leg 79-545-55-5, 4 cm. 2a–c DSDP Leg 79-545-55-CC, 7 cm. 3a–c, DSDP Leg 79-545-55-5, 4 cm. 4a–c, DSDP Leg 79-545-55-CC, 7 cm. 5a–c, DSDP Leg 79-545-55-CC, 7 cm. 6a–c, DSDP Leg 79-545-55-CC, 7 cm. 7a–b, DSDP Leg 79-545-55-CC, 7 cm. 8a–b, DSDP Leg 79-545-55-CC, 7 cm. 9a–b, DSDP Leg 79-545-55-CC, 7 cm. 10a–b, DSDP Leg 79-545-55-CC, 7 cm. 11a–b, DSDP Leg 79-545-55-5, 4 cm. 12a–b, DSDP Leg 79-545-55-5, 4 cm. 13a–b, DSDP Leg 79-545-55-CC, 7 cm. 14, Globigerinelloides barri. 14a–b, Lesches en Diois L10. Scale bars represent 200 µm in 1a–b–14a–b; 10 µm in 1c, 2c–6c.

676

D. Verga, I. Premoli Silva / Cretaceous Research 24 (2003) 661–690

1a

3a

5a

7a

9a

1b

3b

.3c

5b

5c

7b

9b

2b

2a

7c

9c

2c

4a

6a

8a

10a

4b

4c

6b

6c

8b

8c

10b

10c

Fig. 10. 1–10, Globigerinelloides barri. 1a–b, Lesches en Diois L9. 2a–c, Lesches en Diois L13. 3a–c, DSDP Leg 79-545-55-5, 4 cm. 4a–c, DSDP Leg 79-545-55-CC, 7 cm. 5a–c, DSDP Leg 79-545-55-CC, 7 cm. 6a–c, DSDP Leg 79-545-55-5, 4 cm. 7a–c, DSDP Leg 79-545-55-5, 4 cm. 8a–c, Lesches en Diois L10. 9a–c, DSDP Leg 79-545-55-CC, 7 cm. 10a–c, DSDP Leg 79-545-55-5, 4 cm. Scale bars represent 200 µm in 8a–b; 100 µm in 1a–b–10a–b; 10 µm in 2c–9c; 2 µm in 8c, 10c.

Coiling mode

Test in side view

Growth

Peripheral outline

Shape of the chambers

Number of chambers Wall on the earliest chambers Species

Semi-involute to Inflated involute

Rather slow and gradual

Ovoid to subcircular slightly lobate

8–10

Mainly pustulose

G. barri

Evolute

Slow and gradual Rather fast Rather slow and gradual

Hexagonal, more or less lobate Ovoid, slightly lobate Ovoid to subcircular, slightly lobate

Subglobular, reinform in axial view; possible presence of one or more paired final chambers Globular to subglobular

6–7 (rarely)

Rarely pustulose

G. aptiensis

Globular to subglobular Subspherical to subtrapezoidal

7–9 10–12

Mainly pustulose Mainly pustulose

G. ferreolensis G. algerianus

Inflated

Compressed

D. Verga, I. Premoli Silva / Cretaceous Research 24 (2003) 661–690

Table 3 Schematic species key for large, many-chambered representatives of the genus Globigerinelloides.

677

678

D. Verga, I. Premoli Silva / Cretaceous Research 24 (2003) 661–690

Table 4 Distribution of the large, many-chambered Globigerinelloides species in the Cismon core (Venetian Alps, NE Italy). Abbreviations: mbwh, meters below well head; G.aptiensis, Globigerinelloides aptiensis; G. ferreolensis, Globigerinelloides ferreolensis; W, washed sample (shale, marlstone, marly limestone); TS, thin section; R, radiolarian level; P, acetate peel; * occurrence in thin section; light grey pattern, SelliLevel. Core

Centimetre

Mbwh

Kind of sample

G. aptiensis

G. ferreolensis

9 9 9 9 9 9 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12

133 139 150 176 193 229 5 11–13 43 57–58.5 68 92 100–102 106 116 128–134 145 164 177–180 209–212 222 238–240 252 298 1–4 4–10 10–13 22 45 74–76 84–84.1 100 143–145 158–161 184–186 196 245 271 281–284 290–293.5 8 37–42 64 69–71 81–84 88–92 148–152 152–158 162 173 198 209–214 222–225 228 230–234 247–248 253–256.5 256.5–265 278–280 287–292

7.8 7.85 7.96 8.2 8.36 8.7 8.81 8.87 9.17 9.31 9.4 9.63 9.72 9.76 9.86 10 10.14 10.31 10.44 10.7 10.8 11.02 11.14 11.58 11.65 11.69 11.73 11.83 12.05 12.34 12.42 12.57 12.99 13.13 13.38 13.48 13.94 14.19 14.29 14.39 14.52 14.82 15.05 15.11 15.22 15.3 15.86 15.91 15.98 16.08 16.32 16.44 16.56 16.6 16.64 16.78 16.86 16.91 17.08 17.18

P P TS W TS TS TS R TS R TS TS R W TS R TS TS R R TS R TS TS R R R TS TS R R TS R R R TS TS TS R R TS R TS R R R R R W TS TS R R TS R R R R R R

*

* * *

* * *

* r * vr * * r * * *

r *

*

* * vr vr * * vr

* * r * r

R vr

D. Verga, I. Premoli Silva / Cretaceous Research 24 (2003) 661–690

679

Table 4 (continued) Core

Centimetre

Mbwh

Kind of sample

12 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14

290 7–10 11 13–17 20–24 34 53–57 77 94–99 119–127 130 154 164–169 171–175 182 183–186 196–199 202–206 220 227 236 240–241 253–258 255 264–268 5 9 10 25–30 32 35 38 42 48–49.5 55 64 68–70 87 89–90 94 96–97 103–108 113–115 116 121 124 127–128 131 141–145 155 156 167 175 190–192 192 196 199–201 213 222–224 225 227 238–242 253

17.19 17.34 17.37 17.41 17.47 17.59 17.78 17.96 18.17 18.43 18.49 18.72 18.83 18.9 18.99 19.01 19.14 19.2 19.35 19.41 19.5 19.53 19.67 19.68 19.79 19.92 19.96 19.98 20.13 20.18 20.21 20.23 20.27 20.34 20.4 20.48 20.53 20.7 20.73 20.76 20.79 20.87 20.95 20.97 21.02 21.05 21.08 21.11 21.23 21.34 21.35 21.46 21.53 21.67 21.68 21.73 21.77 21.89 21.98 22 22.02 22.15 22.27

TS R W R R TS R TS R R TS TS R R TS R R R W TS W R R TS R W TS W R TS W TS W R W W R W R TS W R R W TS W R W R W TS W W R TS W R W R W TS R TS

G. aptiensis

G. ferreolensis *

vr c * c * f *

vr

vr

*

680

D. Verga, I. Premoli Silva / Cretaceous Research 24 (2003) 661–690

Table 4 (continued) Core

Centimetre

Mbwh

Kind of sample

14 14 14 14 14 14 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16

252–256 257–261 274 281 293–295 298–301 1–3 5–7 9–10 12 15–17 22–25 30–35 37 47 50–52 53 57–60 64 70 72 74 75 75–75.6 77 78 93–95 96 106 114 129 143–147 164–170 180 181 194 200–202 206 235 236–239 247 262–267 268 291 304.5–307 310 4 19 20–28 40 70 69–75 79 93 98 121 117–129 142 157–160 165 185 212 229

22.28 22.33 22.47 22.53 22.64 22.71 22.77 22.81 22.84 22.86 22.9 23 23.06 23.1 23.2 23.23 23.25 23.32 23.36 23.41 23.43 23.45 23.46 23.47 23.48 23.49 23.63 23.66 23.75 23.83 23.97 24.12 24.33 24.45 24.46 24.59 24.65 24.7 24.97 24.99 25.09 25.25 25.29 25.5 25.65 25.68 25.88 26.02 26.07 26.22 26.51 26.53 26.59 26.72 26.77 26.99 27.01 27.19 27.34 27.41 27.59 27.85 28.01

R R W W R R R R R TS R R R W W R TS R W W R R W R R TS R W TS TS TS R R TS R W R TS TS R W R TS TS R TS W TS R TS TS R W TS W TS R W R TS TS W TS

G. aptiensis

G. ferreolensis

vr

vr vr

vr

*

vr vr r

* vr

*

*

*

D. Verga, I. Premoli Silva / Cretaceous Research 24 (2003) 661–690

681

Table 4 (continued) Core

Centimetre

Mbwh

Kind of sample

16 16 16 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 18 18 19 19 19 20 20 21 21

258 285 288 19.5–27 30 32–37.5 37.5–42 45 69 74–81 83 99 112–114 126–130 129 148.5–152 159 177–183 196 195–198 206–210 211 217 230 234–235 240 251–257 261 279–284 97 265 10 96 146 97 273 100 123

28.29 28.54 28.57 28.85 28.92 28.97 29.01 29.06 29.29 29.36 29.42 29.57 29.7 29.85 29.86 30.05 30.14 30.34 30.49 30.5 30.6 30.63 30.69 30.81 30.85 30.91 31.04 31.1 31.29 32.3 33.91 34.21 35.02 35.49 36.66 38.32 39.65 39.86

TS TS W R TS R R W TS R W TS R R TS R TS R TS R R W TS TS R TS R TS R W W W W W W W W W

whole diagnostic specimens were extracted only from the radiolarian levels as silica-replaced individuals, preventing accurate identification of the microstructural features. The few marly layers are still barren or yield very rare, poorly preserved specimens (see Table 4); this may indicate that either dissolution affected the fauna within the marly layers or that at the time of deposition of the latter the environmental conditions continued to be unstable. The species found here are still attributable to Globigerinelloides aptiensis and G. ferreolensis. The Calabianca section is similar to the Cismon core in that many-chambered globigerinelloidids are reported from the lowermost Aptian as small individuals belonging to Globigerinelloides aptiensis, immediately followed by few, seven-chambered specimens with a faster growth assigned to G. ferreolensis. Again, just above the Selli Level, the many-chambered globigerinelloidids found belong to G. aptiensis and G. ferreolensis (see Table 5).

G. aptiensis

G. ferreolensis

vr

vr

*

As far as dimensions, frequency and abundance are concerned, the many-chambered globigerinelloidids within this interval at Calabianca show the same patterns recorded in the Cismon core. They become much more frequent, abundant, larger and better preserved above the Selli Level, allowing recognition of many individuals belonging to Globigerinelloides aptiensis and few specimens assigned to G. ferreolensis. Finally, as in the Cismon core, the poor preservation of the planispiral individuals at Calabianca prevented certain identification of their microstructural features. No G. barri nor G. algerianus were found either in the Cismon core or at Calabianca (Fig. 11), owing to the fact that both of these successions are truncated, corresponding to the lower part of the G. ferreolensis Zone, and the Upper Aptian to Lower–Middle Albian interval is missing (Bellanca et al., 2002; Verga and Premoli Silva, 2002).

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Fig. 11. Stratigraphical ranges of the large, many–chambered Globigerinelloides species in the Cismon core and Calabianca section. Light grey pattern, Selli Level. Abbreviations: G. aptiensis, Globigerinelloides aptiensis; G. ferreolensis, Globigerinelloides ferreolensis; G. blowi Zone, Globigerinelloides blowi Zone; L. cabri Zone, Leupoldina cabri Zone; G. ferreolensis Zone, Globigerinelloides ferreolensis Zone; T. primula Zone, Ticinella primula Zone.

In the Lesches en Diois section, G. aptiensis first occurs in the lowermost sample studied (lower part of the Leupoldina cabri Zone, lower Upper Aptian) extending through the G. algerianus Zone up to the Hedbergella trocoidea Zone (Upper Aptian). Few individuals belonging to G. ferreolensis were found in the upper part of the L. cabri Zone (see Table 6, Fig. 12); this species extends up to the same level as G. aptiensis in the H. trocoidea

Zone. Globigerinelloides barri ranges through the G. ferreolensis and G. algerianus zones. Finally, the distribution of G. algerianus coincides with the eponymous total range zone. The upper range of the large globigerinelloidids is best recorded in DSDP Site 545, where Globigerinelloides specimens are one of the most important component of the planktonic foraminiferal association

D. Verga, I. Premoli Silva / Cretaceous Research 24 (2003) 661–690

683

Table 5 Distribution of the large. many-chambered Globigerinelloides species in the Calabianca section (NW Sicily); for symbols see Table 4. Sample

Metre Kind of sample

CB 33 CB 32 CB 31 CB 31 CB 31 nc CB 30 CB 30 CB 30 nc CB 29 CB 29 CB 28 CB 28 CB 27 CB 27 CB 26 CB 26 CB 25 CB 25 CB 24 CB 24 CB 23 CB 23 CB 22 CB 22 CB 21 CB 21 Selli 6 CB 20 CB 20 CB 19 CB 19 CB 19 lat

1.14 1.2 1.28 1.28 1.28 1.41 1.41 1.41 1.58 1.58 1.63 1.63 1.69 1.69 1.74 1.74 1.8 1.8 1.89 1.89 1.97 1.97 2.03 2.03 2.08 2.08 2.19 2.29 2.29 2.41 2.41 2.41

W TS W TS W W TS W W TS W TS W TS W TS W TS W TS W TS W TS W TS W W TS W TS W

G. aptiensis

G. ferreolensis *

* r/f

*

*

* r

*

*

* *

r/f

r

* * r

r

(Fig. 12). Large globigerinelloidids are abundant and evenly distributed through the whole succession (see Table 7), and at some levels they are excellently preserved, yielding the original calcitic wall. Globigerinelloides aptiensis and G. ferreolensis exhibit the same stratigraphical distribution ranging from the lowermost sample (G. ferreolensis Zone) to the lower part of the Ticinella bejaouaensis Zone (uppermost Aptian). Globigerinelloides algerianus identifies the eponymous zone, which according to our data is more extended upward with respect to that reported by Leckie (1984). Globigerinelloides barri displays the same distribution as G. algerianus, although very rare specimens were found in a single sample from the lower part of the T. bejaouaensis Zone. According to the distribution of globigerinelloidids reported above, there is little space at DSDP Site 545 to accommodate the Hedbergella trocoidea Zone, because Globigerinelloides algerianus disappears in Core 50-3, 54–56 cm, while the next sample studied (ca. 3.2 m above) yields specimens of Ticinella bejaouaensis, which identifies the eponymous zone. Therefore, at this site

Sample

Metre

Kind of sample

G. aptiensis

G. ferreolensis

Selli 4 Selli 3 Selli 2 Selli 1 CB 18 CB 18 CB 18 CB 18 CB 17 CB 17 S7 S6 S5 S4 CB 16 S3 S2 CB 15 S1 SF SE CB 14 SD SC CB13 SB CB 12 CB 12 SA CB11 CB 10 CB 10

2.43 2.45 2.5 2.55 2.6 2.63 2.66 2.69 2.78 2.78 2.89 2.92 2.98 3.06 3.13 3.28 3.35 3.42 3.6 3.87 3.95 4.03 4.03 4.08 4.13 4.13 4.22 4.22 4.22 4.55 4.89 4.89

W W W W W W W W W TS W W W W W W W W W W W W W W W W W TS W W W TS

f

r

bl bd al ad

r vr vr r r vr

vr

r/f r/f r va c

vr

the H. trocoidea Zone might be within the unsampled interval or missing altogether (Fig. 12). From an evolutionary point of view, according to Banner and Desai (1988), the six or more-chambered Globigerinelloides seem to have originated from species of Blefuscuiana such as B. globigerinelloides lobulata Banner and Desai, 1988, which becomes pseudoplanispiral in the outer whorl. These authors also stated that the oldest known species of Globigerinelloides is G. ferreolensis, represented by seven-chambered specimens appearing in the Leupoldina cabri Zone, the upper part of which yields eight-chambered G. ferreolensis. Globigerinelloides algerianus originates from the latter taxon which in turn evolved into ‘Planomalina’ cheniourensis Sigal (Sigal, 1966b). Banner and Desai (1988) considered G. ferreolensis and its descendant to be macroperforate. However, in 1996 BouDagher-Fadel considered that the small, few-chambered Globigerinelloides (Blowiella for this author) originated from a trochospiral praehedbergellid in the Late Barremian and ‘had many descendants’; for BouDagher-Fadel (1996) this implies that all the planispiral species descended one from the

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Table 6 Distribution of the large. many-chambered Globigerinelloides species in the Lesches en Diois section (SE France). Abbreviations: G. aptiensis. Globigerinelloides aptiensis; G. ferreolensis. Globigerinelloides ferreolensis; G. barri, Globigerinelloides barri; G. algerianus, Globigerinelloides algerianus; for symbols, see Table 4. Sample Meter G. aptiensis L L L L L L L L L L L L L L L L L L L L

20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1

73 72 68 65 64 62.5 62 58 51 46 43 39 35 33 30 26 19 11 10 9

vr

G. ferreolensis

G. barri G. algerianus

vr

vr r f f f/c c a a a c vr va c vr f c

vr r f f f c c/a c r vr

vr c c c r r vr

r va a c

vr

other. This hypothesis is partially contradicted by BouDagher-Fadel et al. (1997), as these authors, when discussing Blefuscuiana speetonensis (p. 132), wrote that ‘the tendency towards planispirality shown by this species suggests that it may be ancestral to multichambered species of Blowiella recorded from stratigraphically younger horizons of the Late Aptian’. Paradoxically, BouDagher-Fadel et al. (1997) later stated (p. 182) that the large, many-chambered Globigerinelloides orginated from ancestral Blowiella (now small, few-chambered Globigerinelloides) in the Late Aptian. Contrary to BouDagher-Fadel (1996) and in part to BouDagher-Fadel et al. (1997) (see above), Moullade et al. (2002) suggested that the six or more-chambered Globigerinelloides originated from a trochospiral hedbergellid. In particular, according to these authors, G. aptiensis evolved from the low trochospiral Praehedbergella kuznetsovae, whilst G. blowi (Blowiella in Moullade et al., 2002) gave rise to Blowiella solida. The latter species is considered here to be a junior synonym of G. aptiensis (see sections 5 and 7 above). Therefore, it is not clear how these ‘two identical taxa’ could have originated from such different ancestors. It seems easier to suppose, in agreement with BouDagher-Fadel (1996), that the planispiral plexus, once it had evolved from an ancestral hedbergellid, was able independently to generate its successive descendants by increasing the number of chambers and developing rugosities. Accordingly, we believe that the ancestor of G. aptiensis should be found

within the small, few-chambered planispiral species (G. paragottisi?); then, in agreement with Gorbachik (1986), G. aptiensis (not Praedbergella kuznetsovae as stated by Moullade et al., 2002), gave rise to G. ferreolensis, as suggested by the few transitional specimens illustrated here (Fig. 6.12, Fig. 7.1–3); the further increase in the number of chambers along with the widening of the umbilical area and the progressive lateral compression of the test with respect to G. ferreolensis led to G. algerianus at the base of the eponymous total range zone. The latter then gave rise to Pseudoplanomalina cheniourensis as the final evolutionary member (see Moullade et al., 2002). This evolutionary trend is supported by the associated gradual changes in wall texture; in fact, G. aptiensis is mainly characterized by a smooth wall, whereas rare individuals with a rougher surface are recorded only from the uppermost portion of the Leupoldina cabri Zone; conversely, the other globigerinelloidids predominantly possess rough surfaces and smooth forms are subordinate. Moullade et al. (2002) also affirmed that G. barri is an intermediate between G. ferreolensis and G. algerianus; they did not attribute any taxonomic and/or evolutionary value to the reniform chambers typical of this species and, in addition, stated that bilobate final chambers have never been observed in the small planispiral plexus. Globigerinelloides barri in our opinion belongs to a different lineage. We suggest that G. barri descended from the small, five-chambered G. blowi on account of more numerous, transversally thicker chambers in the last whorl. Both taxa possess a finely perforate wall, although G. barri also exhibits a rough surface in the early chambers. Moreover, G. blowi and G. barri are the only Early Cretaceous planispiral species possessing reniform chambers in edge view (see Verga and Premoli Silva (2003)); the progressive thickening of chambers may result in the appearance in both species of one or more final paired chambers. This feature is more common in G. barri than in G. blowi. This hypothesis seems to be supported by the occurrence of a few intermediate forms between these two taxa as previously illustrated in the literature (see section 5), and will be fully investigated in a paper in preparation.

9. Systematic palaeontology Genus Globigerinelloides Cushman and ten Dam, 1948, emended Longoria, 1974, emended Verga and Premoli Silva, 2003. Type species. Globigerinelloides algerianus Cushman and ten Dam, 1948, p. 43, pl. 8, figs. 4–6. Globigerinelloides algerianus Cushman and ten Dam, 1948. Fig. 8.9–12, Fig. 9.1–13

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1948 Globigerinelloides algeriana Cushman and ten Dam, p. 43, pl. 8, figs. 4–6. 1966 Globigerinelloides algerianus Cushman and ten Dam; Moullade, p. 125, pl. 9, fig. 15. 1974 Globigerinelloides algerianus Cushman and ten Dam; Longoria, pp. 77–79, pl. 6, figs. 1–18. 1981 Globigerinelloides algeriana Cushman and ten Dam; Bellier and Chitta, 1981, p. 42, pl. 2, figs. 16–18. 1985 Globigerinelloides algeriana Cushman and ten Dam; Caron, p. 47, fig. 29.5–7. 1986 Globigerinelloides algerianus Cushman and ten Dam; Gorbachik, p. 132, pl. 29, figs. 2–3. 1993 Globigerinelloides algerianus Cushman and ten Dam; Shanin, 1993, p. 422, fig. 6.2. 1997 Globigerinelloides algerianus Cushman and ten Dam; BouDagher-Fadel et al., pp. 182–183, pl. 10.4, figs. 1–10. Description. Test medium to large, planispiral, moderately to loosely coiled, evolute and laterally compressed; 2–2.5 whorls; 10–12 chambers in the outer whorl increasing gradually and slowly in size as added; first chambers spherical to subspherical, passing to subtrapezoidal and slightly compressed; equatorial periphery subcircular to ovoid, slightly lobate; sutures depressed, radial to slightly curved to sigmoidal; umbilical area wide and shallow; aperture as a low to medium arch bordered by a marked lip; relict openings well extended toward the umbilicus, frequently visible. Wall finely perforate, with the first chambers of the last whorl generally covered by pustules that may coalesce. Dimensions. Maximum diameter: 580 µm; maximum thickness: 190 µm. Remarks. Globigerinelloides algerianus displays a moderate morphological variability regarding the number of chambers of the outer whorl (from 10 to 12), which are more or less loosely coiling, and the peripheral outline ranging from subcircular to more or less ovoid and more or less lobate. Although Banner and Desai (1988) stated that Globigerinelloides (and consequently the type species) differs from Blowiella in possessing a macroperforate wall, we agree with BouDagher-Fadel (1995) in affirming that G. algerianus, the type species of Globigerinelloides, possesses a finely perforate wall. Globigerinelloides algerianus differs from its ancestor, G. ferreolensis, in having (1) more numerous chambers in the outer whorl (10–12 instead of 7–9), (2) a laterally compressed test, (3) slower growth of the chambers, (4) a more loosely coiled spire and (5) a larger and shallower umbilical area. Distribution. Upper Aptian, Globigerinelloides algerianus Total Range Zone. Globigerinelloides aptiensis Longoria, 1974 Fig. 6.1–11

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1959 Planomalina escheri Kaufmann; Bolli, p. 260, pl. 20, figs. 7–8. 1974 Globigerinelloides aptiense Longoria, p. 79, pl. 4, figs. 9–10; pl. 8, figs. 4–6, 17, 18. 1986 Blowiella solida Krechmar and Gorbachik, p. 123, pl. 27, fig. 3. 1994 Globigerinelloides aptiense Longoria; Coccioni and Premoli Silva, p. 679, fig. 13.16–21. 1997 Blowiella solida Krechmar and Gorbachik; BouDagher-Fadel et al., p. 181, pl. 10.2, fig. 4. 1997 Alanlordella aptiensis (Longoria); BouDagherFadel et al., p. 212, pl. 12.2, figs. 1–3. 1998 Blowiella sp. 1; Moullade et al., p. 206, pl. 5, figs. 9–10. 2002 Globigerinelloides(?) aptiensis Longoria; Moullade et al., p. 131, fig. 4A–E. Description. Test small to medium, planispiral, evolute, laterally inflated; 2–2.5 whorls; 6–6.5 chambers in the outer whorl, increasing gradually and slowly in size as added; chambers from spherical to subspherical, arranged in opposite pairs resulting in a hexagonal peripheral outline; equatorial periphery lobate; sutures straight to slightly curved, radial and depressed; umbilical area rather wide and shallow; aperture a low to medium arch bordered by a thin lip; relict openings observed. Wall finely perforate, mainly smooth. Dimensions. Maximum diameter: 330 µm; maximum thickness: 140 µm. Remarks. Globigerinelloides aptiensis displays some morphological variability mainly regarding the number of chambers of the outer whorl, ranging from 6 to 6.5, and in the periphery outline, which can be more or less slightly lobate. The Upper Aptian individual from Trinidad described by Bolli (1959) as Planomalina escheri Kaufmann (illustrated in his pl. 20, figs. 7–8), is included here in the morphological variability of G. aptiensis as Bolli’s description corresponds perfectly to Longoria’s diagnosis. The poorly illustrated holotype (a tilted, umbilical view) of Blowiella solida (Krechmar and Gorbachik, 1986, pl. 27, fig. 3), is a six-chambered specimen characterized by a slow and gradual growth with a slightly lobate equatorial periphery; in our opinion, this morphotype has the same morphological features as G. aptiensis and, consequently, it is here treated as its junior synonym. The specimen illustrated as Blowiella solida by BouDagher-Fadel et al. (1997, pl. 10.2, figs. 5–6), clearly differs from the holotype of Krechmar and Gorbachik (1986) in possessing five chambers in the outer whorl and a much faster growth rate. This morphotype is here assigned to G. paragottisi Verga and Premoli Silva (2003).

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D. Verga, I. Premoli Silva / Cretaceous Research 24 (2003) 661–690 Table 7 Distribution of the large, many-chambered Globigerinelloides species in DSDP Site 545, Leg 79 (offshore Morocco). Abbreviations: G. aptiensis, Globigerinelloides aptiensis; G. ferreolensis, Globigerinelloides ferreolensis; G. barri, Globigerinelloides barri; G. algerianus, Globigerinelloides algerianus; for symbols, see Table 4. Sample 44 CC 45-4,112 45-5, 45 45 CC 46-3, 4-6 46-5, 12-14 46 CC 47-1, 93-95 47-5, 53-55 47 CC 48-1, 57-59 48-3, 64-66 48-7, 23-25 48 CC 49-1, 28-30 49-4, 21-23 49 CC 50-1, 33-34 50-3, 54-56 50-5, 54-56 50 CC 51-1, 54-56 51-3, 47-48 51-5, 37-39 52-1, 81-86 52-3, 79-81 52-5, 93-96 52 CC 53-2, 71-75 53-4, 63-65 53 CC 54-2, 52-56 54-4, 57-60 54-6, 55-58 54 CC 55-2, 120-122 55-3, 58-60 55-4, 87-89 55-5, 4-6 55-5, 40-42 56-1, 66-68 56-2, 76-78 56-3, 54-56 56-4, 61-63 56-5, 62-64

G. aptiensis

G. ferreolensis G. algerianus G. barri

vr

vr vr

r r r

r r r

r c f c vr

vr c r f

c c r c c r r c c f c c f r r r f vr c c c vr

vr

vr c c f c r c f c c c c c c a f c c c a a r c vr r

vr

f vr vr vr vr vr r c vr c c c f a c c a c a a

vr r r

c c a c r f/c

f f c c

vr

BouDagher-Fadel et al. (1997, pl. 12.2, figs. 1–3) refigured the holotype and paratype of G. aptiensis. They affirmed that these individuals have a macroperforate

687

wall and consequently named them Alanlordella aptiensis; however, no close-up of the wall of these specimens was reported; on the other hand, detailed analysis of the Longoria’s type material (B. Huber, pers. comm., 2001) shows that this taxon does not possess a macroperforate wall. Finally, the individual figured by Moullade et al. (1998, pl. 5, fig. 9) as Blowiella sp.1 falls within the morphological variability of G. aptiensis on account of its six, slowly enlarging chambers resulting in a lobate, hexagonal test. Globigerinelloides aptiensis differs from G. paragottisi Verga and Premoli Silva (2003), on account of (1) its more numerous chambers (6–6.5 instead of 5–5.5) in the last whorl, and (2) a much slower growth rate, resulting in (3) a characteristic hexagonal (instead of ovoid) test. Moreover, G. aptiensis can be easily distinguished from its descendant Globigerinelloides ferreolensis on account of (1) its less numerous chambers (6–6.5 instead of 7–9), (2) a slower growth rate and a hexagonal (instead of ovoid) test, and (3) a more lobate equatorial periphery. Distribution. Barremian/Aptian boundary–uppermost Aptian. Coccioni and Premoli Silva (1994) found this taxon in the mid Upper Barremian of Rio Argos (Spain) and Pflaumann and Krasheninnikov (1978) recorded it from DSDP Site 370, offshore Morocco, in strata dated by calcareous nannofossils and ammonites as Late Hauterivian. Globigerinelloides barri (Bolli et al., 1957) Fig. 9.14, Fig. 10.1–10 1957 Biglobigerinella barri Bolli, Loeblich and Tappan, p. 25, pl. 1, figs. 13–18b. 1961 Biglobigerinella sigali Chevalier, p. 33, pl. 1, figs. 19, 20–23. 1974 Globigerinelloides barri (Bolli, Loeblich and Tappan); Longoria, pp. 80–81, pl. 4, figs. 1–3, 8, 14; pl. 5, figs. 9–16; pl. 27, fig. 19. 1974 ?Globigerinelloides blowi Longoria, pp. 82–83, pl. 4, fig. 7. 1997 ‘Biglobigerinella barri’ Bolli, Loeblich and Tappan; BouDagher-Fadel et al., p. 214, pl. 12.2, figs. 4–9. 1998 Globigerinelloides ferreolensis Moullade; Moullade et al., pl. 5, figs. 4–6. 1998 ?Globigerinelloides ferreolensis Moullade; Moullade et al., pl. 5, fig. 1. Description. Test medium to large, planispiral, semiinvolute, laterally inflated; 2–2.5 whorls; 8–10 chambers in the outer whorl, increasing in size rather slowly and

Fig. 12. Stratigraphical ranges of the large, many-chambered Globigerinelloides species in DSDP Site 545, Cores 56-44 (lithological log from Hinz, Winterer et al., 1984, modified) and Lesches en Diois section (lithological log from Moullade, 1966, modified). Abbreviations: G. aptiensis, Globigerinelloides aptiensis; G. ferreolensis, Globigerinelloides ferreolensis; G. barri, Globigerinelloides barri; G. algerianus, Globigerinelloides algerianus; G. blowi Zone, Globigerinelloides blowi Zone; L. cabri Zone, Leupoldina cabri Zone; G. ferreolensis Zone, Globigerinelloides ferreolensis Zone; G. algerianus Zone, Globigerinelloides algerianus Zone; H. trocoidea Zone, Hedbergella trocoidea Zone; T. bejaouaensis, Ticinella bejaouaensis Zone.

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gradually as added; chambers globular to subglobular, progressively passing to reniform in edge view; gerontic individuals may develop one or more final paired chambers; equatorial periphery circular to subcircular, slightly lobate; sutures straight to slightly curved, radial and depressed; umbilicus moderately wide and rather depressed; aperture as a low arch possibly bordered by a thin lip; relict apertures at time observed. Wall finely perforate, with the first chambers of the last whorl generally covered by pustules that may coalesce. Dimensions. Maximum diameter: 410 µm; maximum thickness: 280 µm. Remarks. This species shows some morphological variability mainly concerning (1) the number of chambers in the last whorl, and (2) the absence/presence of one or more final twin chambers, possibly resulting in (3) a double primary aperture. Biglobigerinella sigali Chevalier (1961) exhibits the same morphological features as Globigerinelloides barri and, therefore, is here regarded as junior synonym of the latter. The seven-chambered individual illustrated by Longoria (1974, pl. 4, fig. 7) as G. blowi is considered to be a juvenile G. barri on account of its reniform chambers in edge view and deep umbilical area. The specimen illustrated by Moullade et al. (1998, pl. 5, fig. 1) as G. ferreolensis that possesses reniform chambers cannot be assigned to this species. It more closely resembles G. barri; however, in having only seven chambers in the outer whorl it does not fully match the original diagnosis of G. barri and is considered here to be a juvenile of the latter species. Globigerinelloides barri differs from G. algerianus on account of its (1) less numerous chambers (8–10 instead of 10–12), (2) slightly faster growth rate, (3) reniform chambers in edge view, and (4) circular (instead of ovoid), (5) laterally inflated (instead of clearly compressed) test; moreover, G. barri may develop one or more final paired chambers. It differs from Globigerinelloides ferreolensis in having (1) a much slower growth rate, resulting in (2) a circular (instead of ovoid) test, (3) reniform chambers in edge view (instead of subglobular), and (4) possibly one or more final paired chambers. Distribution. Upper Aptian. Globigerinelloides ferreolensis (Moullade, 1961) Fig. 7.4-12, Fig. 8.1–8 1961 Biticinella ferreolensis Moullade, p. 4, pl. 1, figs. 1–5. 1966 Globigerinelloides ferreolensis (Moullade); Moullade, p. 123, pl. 9, figs. 1–3. 1974 Globigerinelloides ferreolensis (Moullade); Longoria, p. 84, pl. 5, figs. 7–8; pl. 8, figs. 1–3, 8–15; pl. 14, figs. 7–8; pl. 27, figs. 3–4, 12. 1974 Globigerinelloides macrocameratus Longoria, pp. 85–86, pl. 5, figs. 1–6.

1981 Globigerinelloides ferreolensis (Moullade); Bellier and Chitta, p. 42, pl. 2, figs. 13–15. 1985 Globigerinelloides ferreolensis (Moullade); Caron, p. 47, figs. 29.12–13. 1986 Globigerinelloides ferreolensis (Moullade); Gorbachik, pl. 29, fig. 1. 1987 Globigerinelloides ferreolensis (Moullade); Ben Haj Ali, p. 83, pl. 1, figs. 1–2. 1991 Globigerinelloides ferreolensis (Moullade); Altiner, pl. 16, fig. 1. 1993 Globigerinelloides ferreolensis (Moullade); Shanin, p. 430, pl. 6, fig. 2. 1995 Globigerinelloides ferreolensis (Moullade); BouDagher-Fadel, p. 147, pl. 2, figs. 8–9. 1997 Globigerinelloides ferreolensis (Moullade); BouDagher-Fadel et al., p. 183, pl. 10.5, figs. 1–15. 1998 Globigerinelloides ferreolensis (Moullade); Moullade et al., p. 183, pl. 5, figs. 2–3, non figs. 1, 4–6. Description. Test medium to large, evolute, laterally inflated; 2–2.5 whorls; 7–9 chambers in the outer whorl increasing fairly fast but gradually in size as added; chambers globular to subglobular; sutures straight to slightly curved, radial and rather depressed; equatorial periphery ovoid and moderately lobate; umbilical area medium-sized and depressed; aperture as a low arch bordered by a thin lip; relict apertures observed. Wall finely perforate, with the first chambers of the last whorl generally covered by pustules that may coalesce. Dimensions. Maximum diameter: 425 µm; maximum thickness: 190 µm. Remarks. Globigerinelloides ferreolensis displays a rather small morphological variability mainly regarding (1) the number of the chambers in the last whorls (ranging from 7 to 9), (2) the possible presence of a larger final chamber, and (3) the equatorial periphery that can be more or less slightly lobate. In common with Globigerinelloides algerianus, the well-defined morphology and original diagnosis of G. ferreolensis has prevented misinterpretation of its morphological features. Although Banner and Desai (1988) stated that Globigerinelloides (and consequently the species included in it) differs from Blowiella in possessing a macroperforate wall, we agree with BouDagher-Fadel (1995) in affirming that G. ferreolensis possesses a finely perforate wall. The species Globigerinelloides macrocameratus, erected by Longoria (1974, pl. 5, figs. 1–6), is treated here as a junior synonym of G. ferreolensis, as correctly reported by BouDagher-Fadel et al. (1997). Finally, the specimens figured as G. ferreolensis by Moullade et al. (1998, pl. 5, figs. 1, 4–6) are included in the morphological variability of G. barri on the basis of their reniform, even bilobate outer chambers. Globigerinelloides ferreolensis differs from its descendant G. algerianus in having (1) a laterally inflated (instead of

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compressed) test, (2) faster growth, (3) subglobular to globular (instead of subtrapezoidal) chambers, and (4) a deeper, slightly smaller umbilicus. For the differences from G. aptiensis, see under this species (above). Distribution. Lower–Upper Aptian. The appearance of Globigerinelloides ferreolensis in the Lower Aptian, below the Selli Level, was also reported by Sigal (1966a).

Acknowledgements This paper is a contribution to the Cismon APTICORE project, an international effort within the CRER (Cretaceous Researches Events and Rhythms), funded by a bilateral Italian-USA grant. Our warm thanks go to (1) Brian Huber (Smithsonian) for his valuable help in providing information and figures of type material deposited at the Natural History Museum in Washington, and (2) E. Erba and M. R. Petrizzo for advice and discussions on stratigraphy and taxonomy. The paper benefited greatly from the careful reviews of D. J. Batten and two anonymous referees. We acknowledge the review of the English by B. Walsworth-Bell. We wish to thank A. Rizzi (Institute CNR-IDPA, Milan section) for the numerous SEM photographs and C. Malinverno (University of Milan) for thin section preparation. The help of G. Pezzi and G. Chiodi (University of Milan) is also acknowledged. This research was supported by MURST-Cofin 2001 and CNR CU99.00704 to IPS.

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