Biflustra savartii (Audouin, 1826)

Zágoršek, Kamil & Gordon, Dennis P., 2013, Late Tortonian bryozoans from Mut Basin, Central Anatolian Plateau, southern Turkey, Acta Palaeontologica Polonica 58 (3), pp. 595-607 : 598

Biflustra savartii auctt.

Fig. 1B–E .

1974 Biflustra savartii ( Audouin, 1826) ; David and Pouyet 1974: 99. 1988 Biflustra savartii ( Audouin, 1826) ; Moissette 1988: 73, pl. 11,

fig. 6.

Referred material.— Altogether eight specimens were studied (four of them illustrated PM2 − T1125 to PM2 − T1127 and PM2 − T1129 ), mainly with smooth dorsal walls and well−preserved lateral communication pores .

Remarks.—This species is frequently listed under the genus Biflustra , however the type species of Biflustra (Recent Biflustra ramosa d’Orbigny, 1852 from the Philippines) is known only from a single specimen that lacks the ancestrular region. Therefore it is not known if the ancestrula is twinned or single. The type species of Acanthodesia is Flustra savartii and Taylor and Foster (1998) prefer to retain this genus pending description of the ancestrula of B. ramosa .

The frontal features of studied specimens are identical with those described by Zágoršek (2010a) from the Moravian Miocene ( Fig. 1B ) as Biflustra savartii . The abfrontal side of the zooids is very smooth, giving evidence that the colony was originally bilamellar and the two layers have separated ( Fig. 1C ). Lateral walls are perforated by well−preserved uniporous and multiporous mural septula (communication pore areas), lacking in Moravian material ( Fig. 1D, E ). The precise taxonomic status of the species Flustra savartii Audouin (1826) and the various forms attributed to it have yet to be resolved, although Taylor and Foster (1998) figured a putative specimen of Flustra savartii from the type area of the Red Sea. For this reason our specimens are referred to as A. savarti auctt.

Stratigraphic and geographic range.—Miocene to Recent, cosmopolitan.

Figures

Fig. 1. Late Tortonian bryozoans from the Başyayla section. A. Exidmonea sp. (PM2−T1124) with very extended frontal gonozooecium from sample BAS 2. B–E. Biflustra savartii auctt. B. PM2−T1127, frontal view of colony, sample BAS 8. C. PM2−T1126, abfrontal view showing three rows of autozooecia with characteristic angled appearance, sample BAS 8. D. PM2−T1125, lateral view of the three autozooecia showing regularly distributed lateral communication pores, sample BAS 4. E. PM2−T1129, detail of lateral communication pores showing multiporous septula, sample BAS 4. F–H. Margaretta sp. F. PM2−T1130, external view showing concealed ovicells (visible as bulges in frontal shield), sample BAS 8. G. PM2−T1131, internal view showing peristomial chamber, with an ascopore situated in the midline of the frontal shield, sample BAS 11. H. PM2−T1132, detail of the aperture of a colony showing linear structures in the peristomial wall, sample BAS 7. I. Margaretta cereoides (Ellis and Solander, 1786) (PM2−P1939) from section Hlohovec (Moravia) showing the smooth interior surface of the peristome. Scale bars A, B, F, 1 mm; C–E, G–I, 100 µm.