Catalog - Ticinella moulladei

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Ticinella moulladei

Citation: Ticinella moulladei Premoli Silva et al., 2009

Type specimens: Pl. 3, Figs. 1a–d (holotype), 2a–c (paratype), and 3a–c to 5a–b. Holotype (Micro-Unimi No. 1975); paratype (Micro-Unimi No. 1976).

Type sample (& lithostrat): core 56, level 215.2 m.

Type age (chronostrat): upper Albian

Type locality: Madagascar, the Diego well, north of Mont-Raynaud.

Type repository: Milan; Micropaleontological Collection, University of Milan, Dipartimento di Scienze della Terra ‘‘Ardito Desio,’’ Italy.

From the material deposited by Sigal in 1979 at the Fribourg Geological Institute, we picked two so-called topotypes, identified as T. bejaouaensis by Sigal, out of his original material (microslide 4, case 9), which initially appeared similar to the holotype. Both specimens (see Pl. 4, Figs. 1a–d, 2a–c) possess a low spiral convexity, 8 and 9.5 globular chambers in the last whorl, respectively, they are loosely coiled, and the chambers increase very gradually in size. The sutures are depressed and straight on both sides, and the umbilicus is wide and shallow. The primary aperture is a low to low-medium arch that is umbilical- extraumbilical in position, almost reaching the periphery and accompanied by at least two to three clear umbilical supplementary apertures. The wall texture in the inner spire and early chambers of the last whorl is coarsely pustulose, as is the wall of T. roberti, with large pustules surrounding the pores. It becomes gradually smoother in the last two or three chambers, which is devoid of perforation cones. Perforations are regularly spaced, rather large (4–8 µm), and similar in size to those of the other ticinellids (see T. roberti in Pl. 1, Figs. 2a–e; Pl. 3, Figs. 6a–c).

Holotype maximum diameter 0.395 mm, thickness 0.150 mm; paratype maximum diameter 0.400 mm, thickness 0.142 mm.

This species is named in honor of Prof. Michel Moullade, for his important, long-lasting contributions to Cretaceous planktonic foraminiferal taxonomy and biostratigraphy.

Remarks. In addition to the Diego well (Madagascar), the same characters have been observed in three other specimens, collected by MC from Caravaca, Spain (courtesy of F. Allemann), which are associated with late Albian B. breggiensis. These are illustrated in Plate 3, Figures 3–5, including a specimen (Pl. 3, Fig. 4a–c) that was figured in Caron (1985, fig. 36.2a–c) as T. bejaouaensis. From SEM analysis, the wall structure in all these specimens is typical of the ticinellids.

This taxon resembles Paraticinella eubejaouaensis in gross morphology concerning the number of chambers in the last whorl, their gradual size increase, globularity, loose coiling in a low trochospire, wide umbilicus, and presence of straight, depressed sutures. This similarity may account for the lumping of the holotype and paratype of Sigal’s (1966) Ticinella bejaouaensis into a single species. On the other hand, the presence of true umbilical supplementary apertures and the typical Ticinella wall surface prevent consideration of this taxon as congeneric with P. eubejaouaensis. It differs from Ticinella primula Luterbacher, 1963, with which it shares a flat trochospire, by having a larger size, more numerous chambers that are more loosely coiled, at least 8 and up to 10 chambers that gradually increase in size as added in the last whorl (instead of an average of 7 chambers), an umbilical area that tends to be larger, and a wall surface with strong ornamentation close to that of the advanced ticinellids (see Pl. 3). In contrast, the wall surface of T. primula is only slightly rugose.

This taxon differs from the coeval Ticinella roberti plexus by having a flat to very low, loosely coiled trochospire, a much larger and shallow umbilicus, and a very gradual increase in size of the globular chambers throughout the last whorl. It differs from Ticinella praeticinensis by the absence of a pinched margin. In conclusion, it is our opinion that the taxon described above belongs to a new species, here named Ticinella moulladei n. sp.

Occurrence. It is associated with Biticinella breggiensis and Ticinella roberti in upper Albian strata from Madagascar and Spain.

References:

Caron, M. (1985). Cretaceous planktic foraminifera. In, Bolli, H. M., Saunders, J. B. & Perch-Nielsen, K. (eds) Plankton Stratigraphy. CUP, Cambridge 17-86. gs

Premoli Silva, I., Caron, M., Leckie, R. M., Petrizzo, M. R., Soldan, D. & Verga, D. (2009). Paraticinella n. gen. and taxonomic revision of Ticinella bejaouaensis Sigal, 1966. Journal of Foraminiferal Research. 39: 126-137. gs

Sigal, J. (1966). Contribution á une monographie des Rosalines. I. Le genre Ticinella Reichel, souche des Rotalipores. Eclogae Geologicae Helvetiae. 59: 185-217. gs O

CATALOG OF ORIGINAL DESCRIPTIONS: Ticinella moulladei Premoli Silva et al., 2009

Ticinella moulladei

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