Calyptotheca sidneyi, Martino & Taylor, 2018

Martino, Emanuela Di & Taylor, Paul D., 2018, Early Pleistocene and Holocene bryozoans from Indonesia, Zootaxa 4419 (1), pp. 1-70 : 33-37

Calyptotheca sidneyi n. sp.

( Figs 92–105 ; Tables 21, 22)

Calyptotheca capitifera: Harmer, 1957: 1010 , pl. 48, figs 1–3.

Figured material. Holotype, NHMUK 1980.2.1.9A, Recent, Siboga Expedition, Station 99, north Ubian, Sulu Archipelago, 16–23 m; paratype, NHMUK 1980.2.1.7, Recent, Siboga Expedition, locality not recorded; RGM.1350567, RGM.1350568, RGM.1350569, Holocene, UPGG 041, off South Sulawesi.

Diagnosis. Colony encrusting or erect. Autozooids with nodular, evenly pseudoporous frontal shield. Orifice subcircular with elongate condyles that run subparallel to the proximolateral orifice margin, sinus wide, enlarged in ovicellate zooids. Vicarious avicularia with pseudoporous frontal shield extending for half of the avicularium total length, and spatulate rostrum bearing a variable number of solid spines distally. Ooecium globular, covered by secondary calcification formed by the neighbouring zooids and separated by thin raised sutures.

Etymology. Named after Sidney F. Harmer who first studied this species from the great collection of bryozoans made by the Siboga Expedition.

Description. Colony encrusting, multiserial, unilaminar or erect with 2–4 alternating rows of back-to-back zooids bifurcating dichomotously at angles of 70–90˚. Autozooids distinct by a thin, raised rim of smooth calcification, arranged in parallel rows, with zooids diverging outwardly from the colony axis, rectangular to irregularly polygonal, longer than wide (mean L/W = 1.45). Frontal shield slightly convex, nodular, evenly perforated by 50–70 large, circular pseudopores, 15–20 µm in diameter, set in polygonal depressions; marginal areolar pores distinguishable at zooidal corners. Orifice dimorphic; in autozooids subcircular, almost as long as wide, the rounded anter separated from the wide, shallow sinus by a pair of large, elongate condyles that run subparallel to the proximolateral orifice margin; orifice enlarged in ovicellate zooids. Peristome developed proximally as a narrow, nodular, imperforate shelf sloping inwards. Vicarious avicularia randomly placed, as long as autozooids but slightly narrower (mean L/W = 1.79), rectangular to rhomboidal, frontal shield having the same appearance as in autozooids occupying about half of total length; rostrum vaguely spatulate, increasingly widening distally, opesia spoon-shaped; a variable number of solid conical spines (2–4) at its distal end, 20–25 µm in diameter tapering at the tips. Ooecium large, globular, broader than long, covered by secondary calcification formed by the three distal and distolateral neighbouring zooids and separated by thin raised sutures. Openings may be sealed by secondary calcification with ontogeny.

N, Number of colonies and number of zooids measured; SD, standard deviation; *ovicellate zooids; Vic, vicarious; Av, avicularia.

Remarks. A single encrusting colony on a bivalve shell and five erect fragments of Calyptotheca sidneyi n. sp. were found in our samples. Harmer (1957) identified Recent material of this species as Calyptotheca capitifera ( Canu & Bassler, 1929) , originally described from off Jolo in the Philippines at 36.5 m depth. After the examination of the type specimen of C. capitifera , USNM 8048 ( Figs 106–109 ), this species seems to fit best within the definition of Figularia Jullien, 1886 . Figularia capitifera n. comb. is characterised by a rather reduced costal shield ( Fig. 107 ), conspicuously developed pores in the gymnocyst and an ooecium with a large pore medioproximally. The type-species of Figularia , F. figularis ( Johnston, 1847) , differs in having bifenestrate ovicells. However, the range of morphological variation in the genus is so great that species representing the extremes might be considered to belong in different genera ( Gordon 1984).

N, Number of colonies and number of zooids measured; SD, standard deviation; *ovicellate zooids; Vic, vicarious; Av, avicularia.

Recent and fossil specimens of C. sidneyi n. sp. show the same diagnostic features and measurements fall in the same range of variability (mean L/W = 1.45 in the fossils vs mean L/W = 1.49 in the Recent; mean VAvL/ VaVW = 2 in the fossils vs mean VaVL/VaVW = 1.86 in the Recent; see also Tables 21, 22), although the orifice of ovicellate zooids is larger in the Recent specimens than the fossils. The undefined boundaries of the ooecium prevented the measurement of this character in the Recent material, but the ovicells seem larger than in the fossils. The presence of the same type of vicarious avicularia, along with morphology and size of the zooids, in both the encrusting and erect fossil specimens confirms that they are conspecific. No avicularia were observed in Recent erect colony fragments.

Figures

FIGURES 92–95. Calyptotheca sidneyi n. sp., holotype, NHMUK 1980.2.1.9A, Recent, north Ubian, Sulu Archipelago, Philippines. 92. Autozooids and vicarious avicularium. 93. Close-up of the avicularium rostrum showing four solid spines. 94. Group of zooids and vicarious avicularium. 95. Close-up of an ooecium. Scale bars: Figs 92, 94 = 200 µm; Figs 93, 95 = 100 µm.

FIGURES 96, 97. Calyptotheca sidneyi n. sp., paratype, NHMUK 1980.2.1.7, Recent, locality not recorded. 96. General view of an erect colony fragment. 97. Close-up of autozooids at colony bifurcation. Scale bars: Fig. 96 = 200 µm; Fig. 97 = 100 µm.

FIGURES 98–105. Calyptotheca sidneyi n. sp., Holocene, UPGG041, off South Sulawesi. 98–102. RGM.1350567. 98. General view of the encrusting colony. 99. Close-up of an autozooid, a vicarious avicularium and an ovicellate zooid. 100. Close-up of a vicarious avicularium. 101. Close-up of an orifice. 102. Close-up of an ooecium. 103, 104. RGM.1350568. 103. General view of an erect colony fragment. 104. Close-up of a vicarious avicularium. 105. RGM.1350569, group of autozooids from an erect colony fragment. Scale bars: Fig. 98 = 1 mm; Figs 99, 100, 102, 104 = 100 µm; Fig. 101 = 50 µm; Fig. 103 = 400 µm; Fig. 105 = 200 µm.

FIGURES 106–109. Figularia capitifera (Canu & Bassler, 1929) n. comb., holotype, USNM 8048, Recent, Jolo, Philippines. 106. Group of zooids and vicarious avicularia. 107. Close-up of the orifice, with and without operculum. 108. Group of ovicellate zooids. 109. Close-up of a vicarious avicularium. Scale bars: Fig. 106 = 500 µm; Figs 107, 109 = 100 µm; Fig. 108 = 200 µm.