Endoxocrinus (Diplocrinus) alternicirrus sibogae ( Döderlein, 1907 ), Doderlein, 1907

David, Jerome, Roux, Michel, Messing, Charles G. & Ameziane, Nadia, 2006, Revision of the pentacrinid stalked crinoids of the genus Endoxocrinus (Echinodermata, Crinoidea), with a study of environmental control of characters and its consequences for taxonomy, Zootaxa 1156, pp. 1-50 : 42

Endoxocrinus (Diplocrinus) alternicirrus sibogae ( Döderlein, 1907)

Figures 13 c–d.

Synonym: Isocrinus sibogae Döderlein, 1907: 18 ; Endoxocrinus sibogae A. H. Clark, 1908b: 152 ; Cenocrinus (Diplocrinus) sibogae Döderlein, 1912: 20 –21; Diplocrinus sibogae A.H. Clark, 1923: 11 ; Diplocrinus aff. sibogae Bourseau et Roux, 1987: 158 ; Diplocrinus (Diplocrinus) sibogae Bourseau et al., 1991: 259 ; Endoxocrinus (Diplocrinus) alternicirrus var. sibogae David, 1998: 203 (unpublished data); Endoxocrinus (Diplocrinus) sibogae Roux et al., 2002: 820 .

Emended diagnosis

A robust subspecies of E. (D.) alternicirrus with 26–64 arms (mode 40) up to 14.5 cm long (mean 12 cm); arm branching usually isotomous, proximal brachitaxes not contiguous and constricted at articulation 1+2; number of internodals per mature noditaxis 4–8 (mode 6); stalk length relatively short, up to 9.5 cm (mean 7.0 cm); proximalmost diameter usually up to 8.0 mm, greater in the shallowest specimens (mean 6.5 mm); nodals bearing 4–5 cirri, usually 5; length of cirrals 1.2–1.7 mm (mean 1.5 mm).

Type Locality

Off Timor at a depth of 520 m.

Holotype: Catalogue no. 2066, Zoölogisch Museum, Amsterdam; first figured by Döderlein 1907, Pl. 9, Fig. 1 and Pl. 12, Fig. 12 .

Occurrence

Southwestern Pacific from eastern Tasmania and Tonga to the northern Philippines and Timor, at depths from 364 m to 800 m, rarely 970 m (David 1998).

Figures

FIGURE 1. Morphology of diplocrinine crinoids. General external morphology (a), and proximal portion of the stalk and crown showing isotomy (b) or endotomy (c) of arm branching. Facet of the symplexial articulation between columnals (d), and detailed portion of the heteromorphic stalk (e).

FIGURE 12. Variation in noditaxes of the phenotype parrae from the northwestern Atlantic showing local differences.

FIGURE 13. Pacific phenotypes. Specimens from New Caledonia. a and b: alternicirrus phenotype, a: specimen BC 3, b: stalk of specimen TA 20; c and d: sibogae phenotype, specimen BE 8.