The highest occurrence (HO) of Catapsydrax is uncertain due to the uncertain taxonomic affinity of Catapsydrax parvulus, described by Bolli, Loeblich, and Tappan (1957) from the upper Miocene G. mayeri Zone of the Lengua Fm., Trinidad. Kennett and Srinivasan (1983:26, text fig. 7) record this species as ranging above the extinction of C. unicavus (Zone N6= uppermost M3, close to the HO of C. dissimilis) into the late Miocene (Zone N15 = Zone M12). New images of the holotype of Catapsydrax parvulus have been examined (not shown but available at the USNM collection archive) and bring new information, although they do not answer all the questions. The problem is that the holotype specimen is small and poorly preserved. Indications of a coarse wall hint at Catapsydrax, yet there does not appear to be a bulla. The somewhat lateral compression and flattened spiral side are reminiscent of Globorotalia but it could equally be some kind of benthic species. In contrast, the SEM images of C. parvulus of Kennett and Srinivasan (1983, pl. 7, figs. 3-9) have a prominent bulla and are very close to Catapsydrax unicavus, although they are perhaps smaller and more compact than typical. We conclude that the holotype of Catapsydrax parvulus Bolli, Loeblich, and Tappan is not a Catapsydrax, while C. parvulus of Kennett and Srinivasan is, and include the latter in our concept of C. unicavus, including middle Miocene forms (Pl. 4.3, Fig. 13). The total range, therefore, of C. unicavus (and thus Catapsydrax) is lower Eocene to late Miocene Zone M12 based on the observation of Kennett and Srinivasan (1983).

Diagnosis of Catapsydrax can be problematic because bullae occur in several other genera, particularly in the Oligocene. Where preservation permits, distinctions should be possible based on wall texture. Moreover, the bullae in Subbotina, Dentoglobigerina and Globoturborotalita are usually more inflated than in Catapsydrax. Removal or natural breakage of catapsydracid bullae reveals a small primary umbilical aperture, sometimes with a thin lip (Pl. 4.3, Figs. 8, 14). Based on wall texture views of new holotype SEM images, we exclude bulla-bearing Catapsydrax martini scandretti (Blow and Banner, 1962) from Catapsydrax and refer it instead to Globoturborotalita (see Chapter 8, this volume), where it is regarded as a junior synonym of Globoturborotalita martini. Borsetti’s (1959) taxon Catapsydrax venzoi, described from the lower Oligocene of northern Italy, has a bulla similar to C. dissimilis, however it has a much higher spire than is typical. Comparison with the holotype of Subbotina gortanii, originally described as Catapsydrax gortanii Borsetti (1959), which was described from the same locality in Italy and recorded as having the same stratigraphic rage as C. venzoi, suggests these forms are conspecific and we place C. venzoi in synonymy with S. gortanii (Chapter 10, Pl. 10.4, this volume). The similar ‘Catapsydrax-like’ appearance of the wall in these two Italian species we suggest is a function of extensive recrystallization, which is typical of the foraminifera described in Borsetti’s study. [Coxall & Spezzaferri 2018]

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