Celleporaria aperta ( Hincks, 1882 )

Martino, Emanuela Di & Taylor, Paul D., 2018, Early Pleistocene and Holocene bryozoans from Indonesia, Zootaxa 4419 (1), pp. 1-70 : 22-23

Celleporaria aperta ( Hincks, 1882)

( Figs 58–61 ; Table 13)

Schizoporella aperta Hincks, 1882: 126 , pl. 5, fig. 3.

Celleporaria aperta: Gordon et al., 2007: 49 , fig. 2f–g; Taylor & Tan, 2015: 18 , fig. 10A–F.

Figured material. RGM.1350558, Holocene, UPGG 041, off South Sulawesi.

Description. Colony encrusting, multiserial, becoming multilaminar through frontal budding. Basal autozooids subhexagonal, distinct with shallow interzooidal furrows, 350–500 µm long by 230–360 µm wide (mean L/W = 1.45); frontally budded autozooids irregularly arranged, erect, deep-bodied. Frontal shield convex, pustulose, with a peripheral ring of small, subcircular areolar pores, 15–25 µm in diameter. Orifice transversely Dshaped with a distinct rounded pseudosinus placed medially and occupying one-third of the proximal edge; a pair of small, squared condyles present on the proximal part of the anter. Two distolateral oral spine bases may occur, 15 µm in diameter. Suboral avicularium small, placed just below the pseudosinus, rostrum rounded with dentate tip, crossbar complete. Interzooidal avicularia common, irregularly distributed, variable in size, rostrum slightly raised distally, spatulate or lanceolate with dentate tip, crossbar complete. Ooecium hood-like, broader than long, pustulose, imperforate.

N, Number of colonies and number of zooids measured; SD, standard deviation; Av, avicularium; Int, interzooidal.

Remarks. A dozen colony fragments of Celleporaria aperta were found in our samples. This species is distinguished by the rounded proximal pseudosinus of the orifice and the dentate distal tip of the avicularian rostra, the latter character still recognizable in the fossil, partly eroded specimens. Celleporaria aperta is considered as widespread in the tropical and subtropical Indo-Pacific, although differences are apparent in all material attributed to the species. For instance, interzooidal avicularia in Recent specimens from Komodo possess an acutely triangular rostrum ( Winston & Heimberg 1986, fig. 83).

Figures

FIGURES 58–61. Celleporaria aperta (Hincks, 1882), RGM.1350558, Holocene, UPGG041, off South Sulawesi. 58. Group of zooids and interzooidal avicularia variable in size and shape of the rostrum. 59. Close-up of an ovicellate zooid, an interzooidal avicularium with spatulate rostrum, and an adventitious avicularium; both avicularia show the characteristic dentate tip, although abraded. 60. Close-up of an orifice with two oral spine bases and broken suboral avicularium; a single condyle is preserved. 61. Close-up of an interzooidal avicularium with lanceolate rostrum and crossbar preserved. Scale bars: Fig. 58 = 200 µm; Fig. 59 = 100 µm; Figs 60, 61 = 50 µm.