Reedocalymene Kobayashi, 1951

Fortey, Richard A., Wernette, Shelly J. & Hughes, Nigel C., 2022, Revision of F. R. C. Reed’s Ordovician trilobite types from Myanmar (Burma) and western Yunnan Province, China, Zootaxa 5162 (4), pp. 301-356 : 337

Reedocalymene Kobayashi, 1951

Type species. Calymene unicornis Reed, 1917 , Pupaio Formation , Yunnan, original designation .

Discussion. Reed’s (1917) species is the nominated type species of Reedocalymene , although Lu (1975) described much better preserved material of the same genus. In a cladistic analysis of the Subfamily Reedocalymeninae Turvey (2002) showed that Reedocalymene and Calymenesun Kobayashi, 1951 are closely related. Lu (1975, p. 448) had noted this previously, and provided some distinguishing characters, supplemented further by Peng et al. (2000). However, some of these are contradictory. Lu (1975, p. 447) stated of Calymenesun that “the pygidium is quite different from all others of the Calymenids [sic] in having a very narrow border.” On p. 448 he states (of similarity between the two genera) that they share “a broad border on the pygidium”. He stated also that an important feature is the shape of the glabella which is claimed as “semioval” in Reedocalymene , as it is on R. expansa Yi (see Lu, 1975, pl. 46, fig. 4). However, the lectotype of R. unicornis shows a wider part of the glabella at the level of the basal lobes, which is actually more like that of the type species of Calymenesun , C. tingi Sun ( Lu, 1975, pl. 46, figs 9,12). As discussed by Peng et al. (2000) the distinction between the two genera, both erected by Kobayashi (1951), is not clearcut, and they may eventually be synonymized. We follow these authors in recognizing the two genera pro tem.