Palaeocomatella

Summers, Mindi M., Messing, Charles G. & Rouse, Greg W., 2017, The genera and species of Comatulidae (Comatulida: Crinoidea): taxonomic revisions and a molecular and morphological guide, Zootaxa 4268 (2), pp. 151-190 : 184

Palaeocomatella AH Clark, 1912a

Table 1

Type species. Actinometra difficilis Carpenter, 1888 .

Other included taxa (2). Comatella decora AH Clark, 1912b; Palaeocomatella hiwia McKnight, 1977a .

Diagnosis. Mouth central or subcentral in fully developed individuals; up to 20 arms; centrodorsal circular, thick, cirri always present; IBr2 series united by synarthry; IIBr and beyond 2; first syzygy at 3+4 on arms arising from IBr; exterior arms arising from IIBr and following brachitaxes with 1+2 or 3+4, or both; interior arms with 1+2 alone or 1+2, 3+4; distal intersyzygial interval 3–5; distalmost pinnule comb on P3–P6; comb teeth triangular, curved, confluent with outside edge of pinnule; terminal comb tooth fan-shaped.

Distribution. Tropical and temperate Indo-western Pacific from southwestern Japan and possibly Loyalty Ridge off New Caledonia ( P. decora ); New Zealand, the Kermadec Islands, Palau, and southern Indonesia (Kepulauan Kai). Depth range: (?205) 212–808 m (AH Clark 1931; McKnight 1977a; Messing et al. 2000; Messing 2001, 2007).

Remarks. Paleocomatella is distinguished from all other confamilials by its fan-shaped terminal comb tooth. A transverse proximal comb tooth is unique within the genus in P. decora . The distinction between P. hiwia and P. difficilis is unclear, and the two likely represent a single species. Messing et al. (2000) distinguished the two on the basis of distribution of proximal arm syzygies, but Messing (2007) subsequently found both patterns in what is clearly a single species from a single locality. Numbers of P1 comb teeth are similar in both (14–18), and numbers of cirri and cirrals overlap ( McKnight 1977a; Messing et al. 2000; Messing 2001).