Moulladella, Bucur & Schlagintweit, 2018

Bucur, Ioan I. & Schlagintweit, Felix, 2018, Moulladella Jourdanensis (Foury & Moullade, 1966) N. Gen., N. Comb.: Valanginian-Early Late Barremian Larger Benthic Foraminifera From The Northern Neotethyan Margin, Acta Palaeontologica Romaniae 14 (2), pp. 45-59 : 49-50

Genus Moulladella n. gen.

Type species: Meyendorffina (Paracoskinolina) jourdanensis Foury & Moullade, 1966

Derivation of the name: The name is dedicated to Michel Moullade for his numerous contributions to Low- er Cretaceous benthic foraminifera (orbitolinids and others).

Diagnosis: High conical test, dimorphic, with spiral chamber arrangement in the early stage, later becoming uniserial. The early growth stage of the megalospheric specimen consists of an eccentric embryo (biconch?) followed by a small, slightly inclined trochospire with few chambers. Microspheric specimen with voluminous early trochospire with up to two and a half whorls and numerous chambers. The spire may be strongly inclined, eccentric, and almost perpendicular to the cone axis. The septa of the spiral stage, connected by single basal foramina, give rise to the exoskeleton of the marginal zone in the uncoiled part. The exoskeleton consists of few radial partitions (beams) broadening distally and alternating from one chamber to the next. In tangential sections the chamberlets have a triangular-rounded shape and display a cross-wise foraminal system arranged in diagonal lines. The endoskeleton of the central zone consists of irregular distributed, variously shaped (mostly thin) pillars and hemi-pillars, thickened at their bases. They may anastomose forming a labyrinthic network and together with secondary infillings mask the inner structure giving rise to a columella. Irregular arranged foramina in the central zone between the endoskeletal elements, mostly straight. The chamber bases in the central zone are shifted downwards with respect to their marginal counterparts, resulting in a clear separation of both zones. Wall microgranular, and may display a pseudo-keriotheca.

Remarks and comparisons: Concerning the very detailed original description provided by Foury and Moullade (1966) we just remark upon the missing data on dimorphism, namely the prominent initial spire, and the occurrence of a pseudo-keriotheca (discernible only in some specimens). This incompleteness was obviously due to the available material at the disposal of the authors. Foury and Moullade (1966, p. 261) already noted features of their new taxon atypic for the orbitolinids accounting for their generic affiliation with some reservations. Among them, they stressed the clearly separated and complicated central zone (endoskeleton), the shape of the vertical partitions (exoskeletal beams) distinctly broadening distally, and the downward shift of the chamber bases in the central part with respect to the marginal zone.

A rather thick wall with pseudo-keriotheca is present in representatives of the Coskinolinidae Moullade (e.g.,

genus Lituonella Schlumberger ) and Pfenderinidae Smout & Sugden (e.g., genus Conicopfenderina Septfontaine ) but lacking in the thin-walled Orbitolinidae (e.g., Douglass, 1960; Hottinger and Drobne, 1980; Maync, 1972; Schroeder et al., 1975; Septfontaine, 1978; Peybernès, 2004; Vicedo et al., 2014). Except the type of exoskeleton Paracoskinolina? jourdanensis fits all characteristics of the genus Conicopfenderina Septfontaine 2000 (in Kaminski, 2000) non 1988. Without remarking any comparisons or the identity of his Valanginian specimens from Bulgaria with the ones described by Foury & Moullade (1966) from the Barremian of France, Peybernès (2004) described the new species Conicopfenderina? balkanica ( Figs. 2 , 3e–h ). It is believed that M. jourdanensis is characterized by a high intraspecific variability referring to apical angle, size of the test and initial spire, as well as the structure of the central zone (secondary fillings, thickness/coarseness and distribution of endoskeletal elements). Such a variability can be seen within the same assemblage (samples) from both material studied from the Valanginian and Barremian of Romanian and Serbia. A compilation of the biometric data of “ P.” jourdanensis against “ C.” balkanica each taken from the original papers is presented in Table 1. The higher maximum number of chambers in the Valanginian specimens is related to a greater observed test height. Concerning the number of chambers per last mm of the test, Peybernès (2004) didn’t provide data. Our measurements from original illustrations result in 14 to 18. The paratype shown by Foury and Moullade (1968, pl. 1, fig. 3), and reillustrated here in Fig. 3b , displays 15 or 16 chambers per mm. In conclusions, there are overlapping ranges between the two taxa, or only minor differences. These are considered insufficient arguments enabling the creation of a second clear defined species of Moulladella for the Valanginian forms from Bulgaria. It is trivial to mention that two populations from two different stratigraphic and geographic occurrences might show different ecophenotypic variations. We also speculate that the Barremian type-material of “ P.” jourdanensis mostly consists of megalospheric specimens (with reduced initial spire) as can be deduced from the illustrations provided by Foury and Moullade (1968). The type-material of “ C. ” balkanica includes both megalospheric ( Peybernès, 2004, pl. 1,

Tabel 1 Biometric data of Paracoskinolina? jourdanensis (from Foury & Moullade 1968) against Conicopfenderina? balkanica (from Peybernès 2004).

Figures

Fig. 2 Schematic test reconstruction of Moulladella jourdanensis (Foury & Moullade) n. gen., n. comb. modified from Peybernès (2004, fig. 3, for Conicopfenderina? balkanica). Pseudo-kerioteka refers to the thin section 14731 Jerma river, Serbia (above), and RR4027 Kurilovo, Serbia (scale bar = 0.2 mm).

Fig. 3 Paracoskinolina (Meyendorffina) jourdanensis Foury & Moullade, Barremian of France (a–d); holotype specimen in (a) (from Foury and Moullade, 1966, pl. 1, figs. 2–3, 5–6). e–h Conicopfenderina? balkanica Peybernès, Valanginian of Bulgaria; holotype specimen in (f) (from Peybernès, 2004, pl. 1, figs. 7, 1, 8–9).