Biflustra cf. quadrata ( Canu & Bassler, 1929 )

Martino, Emanuela Di & Taylor, Paul D., 2018, Early Pleistocene and Holocene bryozoans from Indonesia, Zootaxa 4419 (1), pp. 1-70 : 9-10

Biflustra cf. quadrata ( Canu & Bassler, 1929)

( Figs 10–12 ; Table 4)

cf. Acanthodesia quadrata Canu & Bassler, 1929: 69 , pl. 1, figs 6–8.

Figured material. RGM.1350545, Holocene, UPGG 041, off South Sulawesi.

Description. Colony erect vincularian; branch fragments quadrangular in cross-section, quadriserial. Zooids arranged in alternating series, separated by shallow grooves between the raised mural rims, rounded rectangular, elongate (mean L/W = 2.25). Mural rim salient, generally narrow, tapering distally, crenulate. Gymnocyst lacking. Cryptocyst with sparse granules, narrow, broadest proximally where it forms a shallow planar shelf expanding into a smooth, plectriform-type apparatus that is long, rectangular, denticulate and curved inwardly. Opesia occupying almost half of the frontal area, elliptical.

Remarks. Five fragments of Biflustra cf. quadrata were found in our samples. The fossil specimens differ from the Recent Philippine specimens in the size of the zooids, which are never less than 700 µm in length in the Recent specimens.

N, Number of colonies and number of zooids measured; SD, standard deviation.

Figures

FIGURES 10–12. Biflustra cf. quadrata (Canu & Bassler, 1929), RGM.1350545, Holocene, off South Sulawesi. 10. Branch fragment. 11. Group of autozooids. 12. Close-up of a zooid showing the denticulate plectriform-type apparatus. Scale bars: Fig. 10 = 1 mm; Figs 11, 12 = 200 µm.