Cushman Foundation Special Publication No. 46 p. 429-458, 2018 Chapter 16 TAXONOMY, BIOSTRATIGRAPHY, AND PHYLOGENY OF OLIGOCENE GLOBIGERINITIDAE (DIPSIDRIPELLA, GLOBIGERINITA, AND TENUITELLA) Paul N. Pearson1, Bridget S. Wade2 and Brian T. Huber3 1School of Earth and Ocean Sciences, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, U.K. Email: [email protected] 2Department of Earth Sciences, University College London, Gower Street, London, WC1E 6BT, U.K. Email: [email protected] 3Department of Paleobiology, MRC 121, Smithsonian Museum of Natural History, Washington, D.C. 20013-7012, U.S.A. Email: [email protected] ABSTRACT The taxonomy, biostratigraphy, and phylogeny of the the family here for the first time. In Dipsidripella Oligocene Globigerinitidae (comprising the genera the wall is often medioperforate (pores 1-2 µm Dipsidripella, Globigerinita and Tenuitella) is reviewed. in diameter; danvillensis-subtype). The following This family is here included in the Superfamily species are recognized as valid and occurring in Globigerinitoidea based on the distinctive wall the Oligocene: Dipsidripella danvillensis (Howe and texture. The group is united by possessing a ‘radially Wallace), Dipsidripella liqianyui Huber and Pearson, crystalline’ wall texture (the glutinata-type wall) Globigerinita glutinata (Egger), Globigerinita uvula which typically bears pyramidal pustules and in (Ehrenberg), Tenuitella angustiumbilicata (Bolli), most species is microperforate (pores <1 µm in Tenuitella gemma (Jenkins), Tenuitella munda diameter). The genus Dipsidripella is included in (Jenkins), and Tenuitella praegemma (Li). INTRODUCTION fine fraction (<150 µm) of seafloor sediment, and are sometimes the dominant component, especially at high Modern Tenuitella and Globigerinita (the latitude sites. Taxonomic discrimination can be difficult two living genera of the Globigerinitidae) inhabit the because of the small size and generalized morphology surface mixed-layer of the open ocean, where they of many of the species. The extinct genus Dipsidripella tend to bloom opportunistically in response to seasonal also comprises small, opportunistic forms, but unlike the nutrient availability, or in upwelling environments (e.g., tenuitellids and globigerinitids it is found predominantly Hemleben and others, 1989; Sautter and Thunell, 1991; in marginal and shelf environments, sometimes where Oda and Yamasaki, 2005; Mohtadi and others, 2009; other planktonic foraminifera are rare or absent. Isotopic Harbers and others, 2010; Wilson, 2012). Multi-species evidence suggests that this genus may have had a partly stable isotopic analysis suggests that their Oligocene and benthic (‘tychopelagic’) life habit (Huber and others, early Miocene predecessors had a similar life habit (Poore 2006:501; Darling and others, 2009; Leckie, 2009). and Matthews, 1984; Pearson and others, 1997; Pearson The most important corpus of work on the and Wade, 2009). Depending on the paleoenvironment, taxonomy of Oligocene microperforate planktonic these genera can be found in very large numbers in the foraminifera is that of Li Qianyu and co-workers Pearson, Wade, and Huber 430 and others, 1995; K&S, 1983 = Kennett and Srinivasan, 1983; WPBP, 2011 = Wade andothers (2011). Wade = 2011 WPBP, and others,1995;K&S,1983=Kennett andSrinivasan,1983; Globigerinitidae Oligocene of relationships phylogenetic inferred and ranges Stratigraphic 16.1. FIGURE 34 33 35 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 GPTS Age (Ma) Cande & Kent (1995) EOCENE OLIGOCENE MIOCENE Epoch LATE EARLY LATE EARLY P22 P16 P18 P19 P20 P17 N5 P 21 N4 N6 Former P Zones (Sub) a b (BKSA, 1995) & tropical a b N Zones (K&S, 1983) E15 E16 M2 M3 O2 O3 O4 O5 O6 O7 O1 M1 E, O and M Zones (Sub) a b (WPBP, 2011) tropical AE10 Huber & Quillévéré Antarctic AE9 AO1 AO2 AO3 AO4 (2005) ? liqianyui Dipsidripella danvillensis insolita T patefacta enuitella praegemma gemma munda angustiumbilicata glutinata Globigerinita uvula ? liqianyui Dipsidripella danvillensis insolita T patefacta enuitella BKSA, 1995 = Berggren Berggren = 1995 BKSA, praegemma gemma angustiumbilicata munda glutinata Globigerinita uvula Chapter 16 - Globigerinitidae (especially Li, 1987; Li and others, 1992; Li and Radford, morphology and the ‘lumped’ approach we have 1991; Radford and Li, 1992). Our taxonomic philosophy taken to the taxonomy than of biological reality. The follows earlier publications of the Paleogene Planktonic Globigerinitidae are of some biostratigraphic utility Foraminifera Working Group (see Pearson and others, (Radford and Li, 1992) and probably have considerable 2006:16-18) in that the classification presented here unrealized potential, especially in high latitude settings. is conservative: we have elected to lump rather than Detailed and quantitative morphometric analysis would split species unless very clear morphological divisions seem the most promising approach for future subdivision can be demonstrated, communicated, and proved to of the group. be of use. We have avoided form-genera, and base our higher taxonomy instead on perceived phylogenetic SYSTEMATIC TAXONOMY relationships. Our approach contrasts with that of Li (1987), Li and Radford (1991), and Li and others (1992) Order FORAMINIFERIDA d’Orbigny, 1826 in the taxonomic re-assignment of some species and Superfamily GLOBIGERINITOIDEA genera, but any worker confronted with abundant and diverse Oligocene microperforate foraminifera should Bermúdez, 1961 have Li’s papers directly at hand. The Globigerinitidae are united by possession of Type genus: Globigerinita Brönnimann, 1951 a distinctive ‘radially crystalline’ wall that on the surface is microperforate and smooth except for numerous DISCUSSION.— Superfamily Globigerinitoidea pustules (described in Chapter 15, this volume, as the comprises the single Family Globigerinitidae. The glutinata-type wall). The wall in Dipsidripella has superfamily level classification in this work follows the more variable pore sizes, making it technically both wall texture observations of Chapter 15 (this volume). micro- and medioperforate, and a somewhat different This superfamily is characterized by the glutinata-type pustule morphology (Huber and others, 2006), but wall (and, in some cases, the danvillensis-subtype). It is otherwise similar. Layering of the wall is often includes the genera Dipsidripella, Globigerinatella, difficult to observe, but can be seen clearly in some Globigerinita, Mutabella, and Tenuitella. The modern dissections. The radially crystalline microstructure species Candeina nitida is genetically close to of the Globigerinitidae is very different from the Globigerinita (Ujiié and Lipps, 2009) and a close microgranular wall of most macroperforate planktonic relationship has also been suggested from the fossil record foraminifera that comprise the Family Globigerinidae. (Blow 1969, 1979). However our own observations This difference in wall texture indicates that the group (unpublished) indicate that Candeina has a very different probably evolved its planktonic habit independently wall texture. Further detailed investigation of both from some other as-yet unidentified benthic taxon. We the genetics and morphology may determine whether suggest that Dipsidripella, which is the first member Candeina should be included in the Globigerinitoidea. of the group to appear in the record during the middle Note that “Superfamily Globigerinitoidea” has been Eocene and may have had a partially planktonic mode employed for a heterogeneous mixture of unrelated of life (Huber and others, 2006), was the ancestor of the micro- and macroperforate taxa by BouDagher-Fadel Globigerinitidae, although morphological intermediates (2012a:145, 206) wherein it was erroneously attributed between Dipsidripella and the first Tenuitella have yet to Carpenter, Parker and Jones (1862). This was later to be discovered. described as a ‘new superfamily’ by BouDagher-Fadel Stratigraphical ranges and inferred phylogenetic (2012b) but the correct attribution is to the author of relationships are shown in Figure 16.1. There seems the original family (Bermúdez, 1961) according to to have been a distinct radiation of Globigerinitidae in the ‘Principle of Coordination’ (International Code of the late Eocene and earliest Oligocene. Globigerinita Zoological Nomenclature, 1999, Article 36.1) which glutinata is one of the oldest of the living ‘species’ states that “a name established for a taxon at any rank of planktonic foraminifera, over 30 million years old. in the family group is simultaneously established for However, this may be more a function of its generalized nominal taxa at all other ranks in the family group”. 431 Pearson, Wade, and Huber Family GLOBIGERINITIDAE Bermúdez, Genus Dipsidripella Brotea, 1995, emended 1961, revised Li, 1987; Pearson and Wade, Huber, Olsson, and Pearson, 2006 2009 TYPE SPECIES.— Dipsidripella hodisensis Brotea, Type genus: Globigerinita Brönnimann, 1951 1995:31, pl. 1, figs. 1-12. Tenuitellidae BouDagher-Fadel (2012a:146) DESCRIPTION. Type of wall: Microperforate to medioperforate, DISCUSSION.— Bermúdez’s (1961) original concept with pore diameters ranging from 0.5-2.0 µm, smooth of this family was based on the globigeriniform test with surface weakly to densely covered by small, blunt morphology and presence of an umbilical bulla. As or, more commonly, hispid pustules; radially crystalline such, it united various macro- and microperforate genera internal structure (glutinata-type wall, danvillensis- with convergent