Polystomella falunica Allix, 1913

Margerel, Jean-Pierre & Poignant, Armelle, 2018, Two poorly known species of Foraminifera: Polystomella minuta Reuss, 1865 from the Oligocene of Germany (Bavaria) and P. falunica Allix, 1913 from the Miocene of western France (Touraine). Designation of a neotype for P. falunica, Geodiversitas 40 (19), pp. 497-504 : 498-500

Polystomella falunica Allix, 1913

Polystomella falunica Allix in Lecointre & Allix, 1913: 45, fig. 9. Elphidium falunicum – Cushman 1939: 46, pl. 12, fig. 5 (non fig. 6). — Margerel 1968: 135, 136, pl. 27, figs 13-14; 1997: figs 4, 9.

Elphidium minutum – Marks 1951: 53, pl. 6, fig. 6. — Kaasschieter in Drooger et al. 1955: 72, pl. 7, fig. 3a, b. — Batjes 1958: 164, pl. 12, fig. 1.

Elphidiella minuta – Kristoffersen 1973: 29, 30, pl. 2, figs 2-5, pl. 4, fig. 3. — Wenger 1987: 295, 296, pl. 13, figs 1, 6. — Cicha et al. 1998: 94, pl. 75, figs 7-8 (pictures of Wenger).

Cribrononion falunicum – Poignant & Pujol 1976: pl. 11, fig. 9. — Sztrákos 1979: pl. 23, fig. 4. — Margerel 1989: pl. 2, fig. 1.

Elphidiella falunica – Cahuzac & Poignant 1996: pl. 2, fig. 6; 2000: figs 8, 17. — Poignant 1997: 88, 89, pl. 4, figs 15, 19. — Rögl 1998: 142, pl. 8, figs 6-7. — Margerel 2009: fig. 20K, L.

ORIGINAL DIAGNOSIS. — “Coquille lisse et brillante montrant extérieurement bien moins de loges que la précédente ( P. crispa (Linné) . Celles-ci visibles au nombre de neuf généralement, sont un peu arquées et triangulaires. Les fossettes septales sont tellement petites qu’on ne peut guère les voir qu’en les colorant au carmin. Elles sont situées le long et très près des sutures. Le contour de la coquille est en carène obtuse. Il n’est pas toujours régulièrement circulaire et forme quelquefois des angles mousses au niveau des sutures. Elle n’est pas ombiliquée comme la P. umbilicata qui a des fossettes bien visibles. Je ne vois aucune espèce décrite qui corresponde à ces caractères.Très commune partout. Diamètre 0,7 mm” ( Lecointre & Allix 1913: 45).

TYPE FORMATION. — Les Faluns de Touraine ( France).

REMARKS

About the synonymy of Elphidium falunicum . “The types came from the Miocene of southern France. I have material from the Miocene, Helvetien, Pontlevoy Touraine; and Salles, Moulin du Minoy; Burdigalien inférieur, Moulin de l’Église, Saucats, Gironde; Le Coquillat, Léognan; Aquitanien supérieur, La Brède, Larriey [sic]; and St. Arit [sic], near Mont de Marsan, France. It is a very distinct species in this region” ( Cushman 1939: 46). Allix (in Lecointre & Allix 1913) makes an error since the type does not come from southern France but from western France. Margerel (1968) identified Allix species and this new specific name will only be used by the French authors. The foreign authors will keep the designations minuta or minutum .

About the synonymy of Elphidium minutum . Marks appears to be the person responsible for confusing the two species.Indeed, in his paper entitled: “A revision of the smaller foraminifera from the Miocene of Vienna Basin” ( Marks 1951), he figures Polystomella falunica under the name Polystomella minuta and calls it Elphidium . He does not speak of P. falunica because we suppose he did not recognise it.

Kaasschieter (in Drooger et al. 1955), working on the Miocene of southwestern France, puts P. minuta and falunica into synonymy and explains his opinion: “Cushman recorded this species ( falunicum ) from some Aquitanian, Burdigalian and Helvetian localities in the Aquitaine basin.Cushman suggested that minutum differs from falunicum in the number of retral processes, but the figures do not show this differences. In our material, this feature shows a variation from 9 to 14. As regards the number of chambers the variation (9 to 15) does not exceed that of Cushman’s figures”.

Batjes (1958) makes an interesting remark: “The few Boom clay specimens have very probably derived from the overlying sand of Antwerp and younger strata”. And, as a matter of fact, the sand of Antwerp is of a Miocene age, and E. falunica seems to be present in Western Europe only from the Miocene.

About the synonymy of Elphidium minuta . To our knowledge, Kristoffersen (1973) is the first to place Polystomella falunica in the genus Elphidiella . He puts into synonymy: Marks, Batjes. He does not recognise Allix species.

About the synonymy of Elphidiella falunica . Poignant (1997), mentions the confusion between Polystomella minuta and P. falunica .

There are also numerous citations from the Miocene without figures and with various specific and generic attributions which concern without any doubt the Allix species. No mention, besides the Allix one, made in Ellis & Messina (1940 and supplements).

DESIGNATION AND DESCRIPTION

OF THE NEOTYPE