As discussed under Family Globigerinidae above, the Working Group now regards Dentoglobigerina as having been spinose in life, at least in its primitive condition. Fox and Wade (2013) illustrated spine holes in the Miocene species D. juxtabinaiensis and Pearson and Wade (2015) illustrated spine holes or possible spine holes in D. galavisi, D. pseudovenezuelana, D. taci, D. tapuriensis, and D. cf. tripartita (= D. eotripartita n. sp. in this work). Here we present additional evidence for spine holes in D. baroemoenensis, D. larmeui, and D. binaiensis. Species for which spine holes have not yet been observed are: D. globosa, D. globularis, D. prasaepis, D. sellii, D. tripartita, D. venezuelana and Globoquadrina dehiscens. It seems that some species in the genus may have been quite densely spinose in life while others were sparsely spinose or even secondarily nonspinose (i.e., lost spines during their evolution). [Wade et al 2018]

Whereas Olsson and others (2006) suggested that Dentoglobigerina was derived from the muricate Eocene genus Acarinina, we now think an origin in the spinose genus Subbotina is much more likely (see discussion under Family Globigerinidae above), as suggested previously for example by Blow (1979) and Bolli and Saunders (1985) (see also Pearson and Wade, 2015). The ancestral form could have been Subbotina yeguaensis, which frequently has an umbilical tooth, and could have given rise to D. galavisi in the middle Eocene (Zone E12). [Wade et al 2018]

According to Blow’s (1979) original definition, the genus requires a globigeriniform morphology and the presence of an umbilical tooth, hence the name Dentoglobigerina. However, observations of modern species e.g., Dentoglobigerina cf. conglomerata and the unrelated Neogloboquadrina dutertrei show that a tooth can vary greatly between individuals and is not always present. As discussed by Pearson and Wade (2015), Blow’s definition would unite a variety of unrelated species and exclude some potentially closely related forms. Some Dentoglobigerina species (e.g., galavisi) consistently have a very prominent umbilical tooth, while in other species the tooth is generally absent (e.g., tapuriensis). Here we emphasize that the umbilical tooth is a variable character and should not be part of the generic diagnosis although it can help in identifying species. We follow Pearson and Wade (2015) by allowing forms without a tooth within the genus Dentoglobigerina but restricting it to D. galavisi and its likely descendants. We exclude various toothed forms with inflated, spherical chambers, which are better placed in Subbotina (see Chapter 10, this volume). [Wade et al 2018]

Several species of Dentoglobigerina are distinctly pustulose, particularly on the umbilical face, with a concentration of pustules in the umbilical region and on the umbilical shoulders. The pustules can be large and abundant, particularly in the species D. sellii. [Wade et al 2018]

The genus Dentoglobigerina, as used here in the phylogenetic sense, includes the D. galavisi - D. globularis - D. altispira globulosa - D. altispira altispira lineage (Text Fig. 20). It includes morphotypes with umbilical teeth over an umbilically restricted aperture. Dentoglobigerina is morphologically intermediate between Globigerina and Globoquadrina. It resembles Globigerina by exhibiting an umbilically restricted aperture and Globoquadrina in possessing one or more umbilical teeth. The genus evolved in the late Oligocene and is largely confined to the Miocene. [Kennett & Srinivasan 1983]

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