Truncatoflabellum Cairns, 1989b

Cairns, Stephen D., 2016, A key to the genera and species of the transversely-dividing Flabellidae (Anthozoa, Scleractinia, Flabellidae), with a guide to the literature, and the description of two new species, ZooKeys 562, pp. 1-48 : 5-6

Taxon classification Animalia Scleractinia Flabellidae

Genus Truncatoflabellum Cairns, 1989b

Flabellum : Milne Edwards and Haime 1848: 257, 259 (in part: flabelline tronquees).- Vaughan and Wells 1943: 226-227 (in part).- Wells 1956: F432 (in part).- Zibrowius 1974: 19 (in part: group 2, but not Blastotrochus nutrix ).

Truncatoflabellum Cairns, 1989b: 60-61; 1994: 75; 1995: 113.- Cairns and Kitahara 2012: 14 (key to genus).

Diagnosis.

Asexual reproduction by apical transverse division of corallum, resulting in distal anthocyathus and basal anthocaulus. Corallum usually laterally compressed and fan shaped, having one or more pairs of thecal edge spines or crests; some species compressed-cylindrical in shape but these always laterally spinose, whereas some fan-shaped coralla lack spines and crests. Columella absent or represented by a fusion of the lower, axial edges of larger septa. Anthocaulus not stereome-reinforced.

Discussion.

The taxonomic history of this genus extends long before it was officially described, and is recounted and discussed by Cairns (1989b). To briefly re iterate, even as early as 1848 Milne Edwards and Haime (1848) placed these species in a section (=subgenus) they called the "flabelline tronquees". Squires (1963: 10, 25) strongly felt that this group of species should be separated as a genus different from Flabellum but ultimately did not take an action, waiting for more biological justification. In Zibrowius’ (1974) revision of the family Flabellidae , he placed the transversely-dividing Flabellum as one of three “groups” in the larger conventional genus Flabellum . Finally, in a paper about the various modes of asexual reproduction, Cairns (1989a) suggested that transverse division represented a key innovation that led to an adaptive advantage for living on soft substrates, justifying the naming of a new genus. But, it was not until later in that year that Cairns (1989b) proposed the name Truncatoflabellum . As of this paper, there are 38 known species in the genus, six of these known only as fossils (Table 1).

Distribution.

Middle Eocene (Bortonian) of New Zealand to Recent: cosmopolitan, except for the Antarctic, northeast Pacific and western Atlantic (generally low species diversity in Atlantic), 2-3010 m.

Type species.

Euphyllia spheniscus Dana, 1846, by original designation.