Pseudonummoloculina aurigerica Calvez, 1988

Reference Illustration & Description

Calvez (1988), pl. 1, text figs. 2-3, p. 393-395.

P. aurigerica is the type species of the genus Pseudonummoculina which is partly defined by the presence of ‘notches/crenulations’ formed by longitudinal ribs in the roof of the chambers which lead to an aperture bordered by what looks broadly similar to a bicycle cog wheel. P. aurigerica is slightly smaller, broader, has fewer (adult) planispiral whorls and fewer chambers per whorl than P? heimi .

No other illustrated material of this species appears to show the apertural notches/crenulations diagnostic of the genus and identification is usually based on biometric similarities (if explained at all). See the Species Key Chart (Appendix) for diagnostic and other characteristics. Piuz & Vicedo (2020) remark on the similarity between this species and their new species Nummoloculinodonta akhdarensis from the middle Cenomanian of Oman (see remarks under that species below). It is also similar to their new species Planinummoloculina gnosi which also possesses a notched/crenulated aperture, but that species is planispiral virtually throughout.

Stratigraphic Distribution

(?Hauterivian) latest Barremian – late Albian (?middle Cenomanian).

P. aurigerica was first described from the late early – middle Albian of the Pyrenees (Calvez, 1988). Since then, its stratigraphic range has been extended. Velić (2007) describes – without illustration – P. aurigerica ranging down to the latest Barremian from the Dinarides of the Balkan countries, although he also states that “…species of Pseudonummoloculina similar to P. aurigerica ” are also found in the latest Hauterivian (Velić, 2007: p. 14). Solak et al. (2021) provides a composite range chart from several sources which shows FADs of P. aurigerica in the latest Barremian (Velić, 2007), uppermost early Aptian (Husinec et al., 2009 and Tešović et al., 2011 – see also Cociuba, 2000), basal Albian (Calvez, 1988; Hottinger et al., 1989 and Mancinelli & Chiocchini, 2006) and intra-Early Albian (Chiocchini et al., 2012 and Arnaud-Vanneau & Premoli-Silva, 1995 – see also Cruz-Abad et al., 2017). Solak et al. (2021) provided illustrations of P. aurigerica from Albian platform limestones of Turkey. The illustrations are plausible, but those authors admitted that none show the notched aperture characteristic of the genus.

In addition, Ghanem & Kuss (2013) reported and illustrated this species (though again with no notched aperture visible) from the early Aptian to the lower late Albian of Syria.

An uncertain specimen has been illustrated from the lowermost Sarvak Formation (late Albian) of the Iranian Zagros (Mohseni & Javanmard, 2020).

Chiocchini et al. (2008, 2012) shows an LAD for this species in the lowermost late Cenomanian, although unillustrated. Chiocchini et al. (2008, 2012) do not recognise a middle Cenomanian substage and so this LAD may be considered to occur within the chronostratigraphic middle Cenomanian. Almost all other records appear to restrict the LAD of P. aurigerica to the Albian (see Solak et al., 2021: p. 690) although they (Solak et al., 2021) list an exception in Velić (2007) from the Dinarides and BouDagher-Fadel et al. (2017) from Tibet. However, the present authors could find no record of this species in that latter publication. In Velić (2007), although the species is mentioned in the text from Barremian to Albian it is for some reason not included on any of Velić’s appropriate range charts for that stratigraphic interval or younger. However in the text of that article it is stated that it “…continued into the Late Cretaceous [i.e. Cenomanian] (Gušić & Jelaska, 1990; Velić & Vlahović, 1994)”. However, P. aurigerica is not mentioned in the latter reference. Dimitrova (1995) described “ Pseudonummoloculina sp. ” from the early Cenomanian of Bulgaria and compared it to P. aurigerica . However, her illustration appears to have closer afinity to Hemicyclammina whitei Henson, although an illustration of “ Ammodiscus cretaceous (Reuss) ” from the same aged strata could be a Pseudonummoloculina . Schlagintweit (1991) recorded forms without apertural notches but assigned to this species from the German Northern Calcareous Alps. He considers these specimens – and perhaps many other Early Cretaceous references to P. aurigerica – as probably attributable to Derventina filipescui Neagu (Dr Felix Schlagintweit pers. comm., 2023). In summary, the Cenomanian occurrence of P. aurigerica is poorly established.

Cenomanian Paleogeographic Distribution

Probably Central Neotethys.

Albian records are widespread (including MIT Guyot in the Pacific (Arnaud-Vanneau & Premoli Silva, 1995; note this form corresponds to the specimens from the upper Aptian of Germany-Austria, Schlagintweit, 1991, pl. 15, figs. 26-29), but uncertain Cenomanian records (see discussion above) are limited to Italy (Chiocchini et al., 2008, 2012) and the Dinarides (Velić, 2007). In both cases, illustrations are lacking.