Bitectiporidae, MacGillivray, 1895

? Bitectiporidae View in CoL sp. indet.

Figure 35 View FIGURE 35

Figured material. PMC EDM-Collection J.H.B.135a, sample 19229 ( Figure 35A–B View FIGURE 35 ) and sample 19231 ( Figure 35C View FIGURE 35 ); Core 19, Daidokutsu cave, Okinawa, Japan, Holocene.

Description. Colony encrusting, multiserial, unilaminar. Autozooids distinct, separated by shallow grooves and a narrow band of smooth calcification outlining the zooidal perimeter, wider proximally (20–30 µm) than laterally (10–20 µm), rounded rectangular in shape with concave proximal and convex distal edge, longer than wide (mean ZL/ZW 1.53). Frontal shield flat to slightly convex, pustulose, with pustules 15–30 µm in diameter and sparse, minute, circular pseudopores, 3–13 µm in diameter, between pustules. Orifice keyhole-shaped, elongate (mean OL/OW 1.33), with horseshoe-shaped anter separated from a narrower, shallow bowl-shaped sinus by two stout triangular condyles, 19–27 µm long by 18–30 µm wide at the base, medially directed or curved proximally; oral spines absent. Avicularia and ovicells not observed.

Measurements (µm). ZL 710±81, 598–847 (2, 10); ZW 464±56, 367–556 (2, 10); OL 191±9, 179–203 (2, 9); OW 144±8, 133–157 (2, 9).

Remarks. Given the scarcity of material as well as the paucity of morphological characters (e.g., the lack of avicularia and ovicells, in both cases probably reflecting our very small sample size rather than a true absence in the species), we can only tentatively assign this taxon to a family. Assignment to Bitectiporidae is based on the presence of the following characters attributed to this family: lepralioid frontal shield that can have pseudopores, orifice with subcircular to oval anter and broad to narrow sinus, condyles that can be present, and spines that can be absent (see Martha et al., 2020). Other options we considered are Echinovadomidae Tilbrook, Hayward and Gordon, 2001 ; Gigantoporidae Bassler, 1935 ; Hippopodinidae Levinsen, 1909 ; and Schizoporellidae Jullien, 1882 . Although these families have an orifice with condyles, the general shape is more subcircular or subquadrangular than elongate and keyhole-shaped. Keyhole-shaped orifices are also typical of families such as Hippaliosinidae Winston, 2005 , in which the lepralioid frontal shield is imperforate, and Cleidochasmatidae Cheetham and Sandberg, 1964 , which again includes genera with imperforate frontal shields except for a row of marginal areolae. Some genera in Phidoloporidae Gabb and Horn, 1862 may also have keyhole-shaped orifice but they are characterized by a denticulate anter.

Superfamily SCHIZOPORELLOIDEA Jullien, 1883

Family TETRAPLARIIDAE Harmer, 1957

Genus TETRAPLARIA Tenison Woods, 1879 View in CoL

Tetraplaria stellifera sp. nov. Di Martino, Rosso and Taylor

Figure 36 View FIGURE 36

zoobank.org/ 70693D67-F6D1-4347-85DA-99AAD3FA285C

Type material. Holotype PMC. B61. 29.7.2024 a, sample 19044 ( Figure 36A–C View FIGURE 36 ); paratype PMC. B61. 29.7.2024 b, sample 19028 ( Figure 36D–G View FIGURE 36 ); Core 19, Daidokutsu cave, Okinawa, Japan, Holocene.

Etymology. Latin, meaning starry, referring to the stellate pattern of the frontal shield pseudopores.

Diagnosis. Tetraplaria with internodes composed by at least 1–2 pairs of zooids, arranged back to back; frontal shield with a tessellated pattern formed by grooves in a rounded polygonal pattern interspersed with stellate pseudopores; orifice sinuate with rectangular condyles; ovicell kenozooidal, notably large, with proximal half flat and imperforate, and distal half sloping and pseudoporous.

Description. Colony erect, jointed; internodes consisting of at least 1–2 pairs of zooids arranged back to back; joints short (50–55 µm) and tubular, c. 100 µm in diameter. Autozooids distinct, separated by thin furrows, club-shaped, tapering proximally, elongate (mean ZL/ZW 2.69). Frontal shield convex, tessellated, featuring a pattern of rounded polygonal grooves, each polygon roughly 20–25 × 30–35 µm, interspersed with circular, stellate pseudopores, 10–17 µm in diameter, pseudopores missing immediately suborally. Orifice surrounded by a flat rim of smooth calcification, broader proximally (c. 18 µm) and tapering laterally and distally (6–9 µm), bell-shaped; anter horseshoe-shaped, sinus shallowly U-shaped occupying less than half the orifice width, condyles rectangular, 10 × 20 µm. Ovicell kenozooidal, globular, large, seemingly closed by zooidal operculum; ooecium proximal portion flat, tessellated and imperforate, distal portion sloping and densely and evenly pseudoporous (4–5 rows of pseudopores); pseudopores similar in size to those of the frontal shield but deeper, stellate pattern uncertain; a distal fissure interpreted as the remnants of the associated kenozooid participating in the development of the ooecium. Ovicellate zooid size (including the ooecium) same as non-ovicellate autozooids, 888 µm in length (including the ooecium) by 285 µm in width; ovicellate zooid orifice size also similar to that of autozooid, 158 × 132 µm. Kenozooid positioned distally to ooecium, in connection with the tubular joint, trapezoidal, 210 × 130 µm in size, functioning as a wedge separating two autozooids.

Measurements (µm). ZL 731±142, 595–889 (2, 4); ZW 272±38, 216–298 (2, 4); OL 156 (1, 1); OW 143 (1, 1); OvL 237 (1, 1); OvW 302 (1, 1).

Remarks. The genus Tetraplaria includes species with small hyperstomial, pseudoporous ooecia immersed in the distal zooid, such as T. ventricosa (Haswell, 1880) , as well as species with internal ovisacs and enlarged fertile zooids, such as T. immersa (Haswell, 1880) . Despite its general resemblance to T. ventricosa (e.g., Gordon and d’Hondt, 1997; Tilbrook, 2006), the new species stands out within Tetraplaria due to its distinctive large kenozooidal ovicell, which also displays a unique perforation pattern, with its proximal portion imperforate and distal portion densely and uniformly pseudoporous. Based on the observation of a single internode with ovicellate zooids, ooecium formation could potentially involve either a distal kenozooid or the distal autozooid, akin to certain species of cribrilinids (e.g., Rosso et al., 2021b) or Microporella (e.g., Di Martino and Rosso, 2021). Furthermore, to our knowledge, the stellate pattern of the frontal pseudopores is unique within the genus.