Bryopesanser minutiporosus, Martino & Rosso & Taylor & Chiu & Fujita & Kitamura & Yasuhara, 2025

Bryopesanser minutiporosus sp. nov. Di Martino, Rosso and Taylor

Figure 41 View FIGURE 41

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Type material. Holotype PMC. B63. 29.7.2024 a, sample 19217 ( Figure 41A–E View FIGURE 41 ); paratype PMC. B63. 29.7.2024 b, sample 19210 ( Figure 41F–H View FIGURE 41 ); Core 19, Daidokutsu cave, Okinawa, Japan, Holocene.

Etymology. Latin, meaning pierced by small pores, referring to the minute size of the lens-shaped pseudopores on its frontal shield.

Diagnosis. Bryopesanser with proximally tubercular frontal shield densely pierced by minute lens-shaped pseudopores; orifice with longer-than-wide drop-shaped sinus, and minutely denticulate condyles; seven oral spines in autozooids, six visible in ovicellate zooids, the proximalmost pair slightly above the proximal margin of orifice; peristome lacking; paired avicularia distolateral to orifice, aligned with the second proximalmost pair of spines, oval; rostrum open, curved towards the orifice, distomedially directed; ooecium smooth, imperforate, with a transverse proximal crest but lacking proximal projection.

Description. Colony encrusting, multiserial, unilaminar. Autozooids distinct, separated by raised sutures and shallow grooves, pentagonal, slightly longer than wide (mean ZL/ZW 1.18), widest proximally, with thick lateral walls (175 µm); small, subcircular pore-chamber windows visible laterally, approximately 20 µm in diameter. Frontal shield slightly convex, convexity more obvious around the orifice, tubercular proximally, tubercles rounded 20–30 µm in diameter, densely pierced by lens-shaped pseudopores, 3–9 µm long; an area of imperforate calcification distinguishable proximally and laterally to orifice; marginal areolae present at proximolateral zooidal corners, 20–25 µm long. Orifice with elliptical anter, slightly convex proximal margin occupied by rectangular, minutely denticulated condyles, 12–14 µm high, and longer-than-wide drop-shaped sinus, 38 µm long by 20–25 µm wide; seven oral spine bases in autozooids, six in ovicellate zooids, 18–28 µm in diameter, with the proximalmost pair slightly above the proximal margin of the orifice; peristome absent. Avicularia adventitious, paired, located distolaterally to orifice, aligned with the second proximalmost pair of spines, oval; rostrum open, curved towards the orifice, distomedially directed; crossbar complete and thick. Ovicell hyperstomial; ooecium cap-like, smooth, imperforate, with thick proximal margin and a transverse crest proximally, lacking a median projection. Intramural budding observed for autozooids with evident concentric rims around the orifice.

Measurements (µm). ZL 534±48, 457–618 (2, 12); ZW 453±70, 331–596 (2, 12); OL (including sinus) 135±9, 122–149 (2, 6); OW 110±11, 98–125 (2, 6); AvL 76±9, 67–91 (2, 14); AvW 59±6, 46–68 (2, 14); OvL 111±9, 104–120 (2, 4); OvW 178±13, 161–191 (2, 4).

Remarks. Bryopesanser minutiporosus sp. nov. differs from its congener from Daidokutsu cave mainly in the absence of a proximal peristome and ooecium projection, as well as in the appearance of the frontal shield, which has minute lens-shaped pseudopores and proximal tubercles in B. minutiporosus sp. nov. but is faintly nodular with multiporous pseudopores in B. inflexus sp. nov. Among Recent species of Bryopesanser lacking a proximal peristome: B. baderae Tilbrook, 2012 has nine oral spines and circular pseudopores; B. hebelomaia Tilbrook, 2012 develops proximal peristomes in ovicellate zooids; B. tilbrooki Winston and Vieira, 2013 from Brazil has a distinctive subquadrate sinus and multiporous pseudopores. The Miocene B. sanfilippoae Di Martino and Taylor, 2015 from East Kalimantan ( Indonesia) also lacks a peristome but differs in having circular pseudopores.