Calyptotheca triquetra ( Harmer, 1957 )

Martino, Emanuela Di & Taylor, Paul D., 2018, Early Pleistocene and Holocene bryozoans from Indonesia, Zootaxa 4419 (1), pp. 1-70 : 37-38

Calyptotheca triquetra ( Harmer, 1957)

( Figs 110–112 ; Table 23)

Schizomavella triquetra Harmer, 1957: 1027 , pl. 66, figs 1–3.

Figured material. RGM.1350570, Holocene, UPGG 041, off South Sulawesi.

Description. Colony encrusting, multiserial, unilaminar. Autozooids distinct, separated by deep interzooidal furrows, irregularly polygonal, longer than wide (mean L/W = 1.22). Frontal shield convex, perforated by numerous, teardrop-shaped to slit-like pseudopores, 15–20 µm long, arranged in radial rows, radiating from the suboral avicularium. Orifice distally placed, slightly broader than long, two small, rounded condyles separate a horseshoe-shaped anter from a narrower, shallow sinus. Suboral avicularium constantly present, median, directed proximally or proximolaterally, pear-shaped. Ooecium large, globular, broader than long, 235 µm long by 310 µm wide, occupying the entire frontal shield of the next distal zooid, with similar pseudopores to those of the frontal shield, radiating from an inconspicuous central umbo.

Remarks. A single colony of Calyptotheca triquetra encrusts a Triphyllozoon fragment. The characteristic perforation pattern of the frontal shield and ooecium distinguishes this species from congenerics. Harmer (1957) recorded C. triquetra from two stations in Flores and Timor East at 0–54 m depth.

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

Figures

FIGURES 110–112. Calyptotheca triquetra (Harmer, 1957), RGM.1350570, Holocene, UPGG041, off South Sulawesi. 110. View of the colony encrusting the dorsal side of a Triphyllozoon fragment. 111. Close-up of three zooids, one of which is ovicellate. 112. Close-up of zooids with vertical and obliquely directed suboral avicularia of different sizes. Scale bars: Fig. 110 = 200 µm; Figs 111, 112 = 100 µm.