Crepidacantha longiseta Canu and Bassler, 1928

Crepidacantha longiseta Canu and Bassler, 1928 View in CoL

Figure 25 View FIGURE 25

v. 1928 Crepidacantha longiseta Canu and Bassler , p. 135, pl. 21, figs. 3, 4.

v. 2001 Crepidacantha longiseta Canu and Bassler ; Tilbrook, Hayward and Gordon, p. 92, fig. 16B.

v. 2006 Crepidacantha longiseta Canu and Bassler ; Dick, Tilbrook and Mawatari, p. 2239, fig. 13g, h.

v. 2016 Crepidacantha longiseta Canu and Bassler ; Dick and Grischenko, p. 231, fig. 32.

Figured material. PMC EDM-Collection

J.H.B.143a, sample 19119; Core 19, Daidokutsu cave, Okinawa, Japan, Holocene.

Description. Colony encrusting, multiserial, unilaminar. Autozooids distinct, outlined by deep furrows, nearly as long as wide (mean ZL/ZW 1.03), rounded hexagonal to pentagonal. Frontal shield flat to slightly convex proximally, becoming more convex around the orifice, coarsely tubercular, imperforate except for a row of circular to elliptical marginal areolae (max diameter 8–20 µm) along the zooid perimeter, often obscured by neighbouring zooids; peripheral spines likely present, a single base, measuring 10 µm in diameter, observed. Orifice keyhole-shaped, with horseshoe-shaped anter, two pointed, downward directed condyles, and an almost straight to faintly convex proximal margin. Paired avicularia laterally to orifice, with rostrum tips at level with orifice condyles, directed proximally. Ovicells not observed.

Measurements (µm). ZL 417±45, 363–496 (1, 6); ZW 406±42, 334–456 (1, 6); OL 90±5, 85–95 (1, 4); OW 83±7, 77–91 (1, 4); AvL 48±3, 45–50 (1, 4); AvW 32±3, 29–35 (1, 4).

Remarks. Two species of Crepidacantha with latero-oral avicularia directed proximally have been previously recorded from Japan (i.e., C. crinispina Levinsen, 1909 and C. longiseta Canu and Bassler, 1928 ) (e.g., Hirose, 2010; Dick and Grischenko, 2017). The two species mainly differ in the curvature of the proximal margin of the orifice, which is flatter in C. longiseta compared to C. crinispina (see Tilbrook, 2006).

We hereby reclassify the family Crepidacanthidae , moving it from the superfamily Mamilloporoidea Canu and Bassler, 1927 to the superfamily Adeonoidea . This decision is based on the molecular phylogenetic analysis conducted by Orr et al. (2022), which demonstrated that Crepidacantha is well nested within Adeonoidea . Shared characters, such as numerous basal pore-chambers, support this reallocation. The previous classification under Mamilloporoidea was primarily due to the superficial similarity of the pseudoporous ovicells.