Clypeaster eurychorius H.L. Clark, 1925c

Filander, Zoleka & Griffiths, Charles, 2017, Illustrated guide to the echinoid (Echinodermata: Echinoidea) fauna of South Africa, Zootaxa 4296 (1), pp. 1-72 : 50-51

Clypeaster eurychorius H.L. Clark, 1925c

Fig. 56 A–D.

Clypeaster humulis: H.L. Clark, 1923: 392 ; H.L. Clark, 1925a: 149.

Clypeaster eurychorius H.L. Clark, 1924: 10 –11. Pl. III; Clark & Courtman-Stock, 1976: 241; Schultz, 2009: 539, Figs 913– 916.

Clypeaster (Stolonclypus) eurychorius: Mortensen, 1948d: 94 –96. Pl. XXX, Fig. 2 . Pl. XXXI, Figs 2 , 3 . Pl. XXXII, Fig. 3 . Pl. XXXIII, Fig. 2 .

Material examined. MBC-A 022261; MBC-A 022286; MBC-A 022290; MBC-A023306; A22330; A28431 ; A23092 .

Identification. Distinguished from other Clypeaster species within the region in having a rounded pentagonal test, flat except at elevated petal area, margin thick. Petals short, opened distally, pore-zones narrow, interporiferous zones wider. Primary tubercles sparse, miliaries smaller than primaries. Primary spines small, slender, longer towards mouth; miliaries slender, with thick tip. Preserved specimens brownish-green; denuded test uniformly yellowish-white.

Global maximum size. Maximum test length 145 mm.

Global distribution. South and East coast regions of South Africa, northward to Pemba Strait (Tanzania) and off Mauritius, at 125–320 m depth ( Mortensen 1948d; Schultz 2009).

Remarks. Deep-water species, burrows in uppermost layer of sediment, where it feeds on organic particles.

Figures

FIGURE 2. Body plan of an irregular echinoid or sand dollar (Clypeaster rarispinus), showing terminology of various body parts.

FIGURE 3. The body plan of an irregular echinoids or heart urchin (Echinocardium cordatum), showing terminology of different body parts.

FIGURE 56. Clypeaster eurychorius (SAMC-A 23306). A. Map showing distribution. B. Aboral view of preserved specimen. C. Oral view of preserved specimen. D. Side view of preserved specimen.