Reedocalymene unicornis (Reed, 1917)

Figs 12.1–6, 8, 10

1917 Calymene unicornis sp. nov.; Reed p. 52–54, pl. 8, figs 10–13.

1951 Reedocalymene unicornis (Reed, 1917); Kobayashi, p. 45, pl. 4, figs 12–14.

1975 Reedocalymene unicornis (Reed, 1917); Lu, p. 447.

2002 Reedocalymene unicornis (Reed, 1917); Turvey, p. 55.

2005 Reedocalymene unicornis (Reed, 1917) Turvey, p. 550.

Material. Lectotype (selected by Turvey, 2005): damaged cephalon, Figs 12.1-3 (Reed, 1917, pl. 8, fig. 10), GSI 11913. Additional type material: cephalic fragments, Figs 12.5 /8 and 12.10/6 (Reed, 1917, pl. 8, figs 12,11 respectively), GSI 11912; pygidium, Fig. 12.4 (Reed, 1917, pl. 8, fig. 13), GSI 11911? All material from the Shihtien Formation (Darriwilian) at Pupiao, western Yunnan.

Discussion. Reed (1917) described the limited material of this species in some detail, and new cast material does not greatly enhance our knowledge. The lectotype is more distorted than Brock’s original drawing suggests, and the upward curvature of the anterior pro/jection shown by Reed (1917, pl. 8, fig. 10a, GSI 11913) may have been exaggerated by this. However, the comparatively laterally expanded L1 on the glabella is probably a real feature, which is not so clear on the original drawing. This differs from other species assigned to the genus by Lu (1975) that have a uniformly deeply parabolic glabellar outline. In this respect R. unicornis more closely resembles species that have been assigned to Calymenesun and Vietnamia (see Turvey, 2002). However, it is possible that deformation may have contributed to this distinction. A very incomplete cranidium shows the outline of the posterior fixed cheek. A backwardly displaced free cheek with a narrow border is best displayed on Reed’s pl. 8, fig. 11; we have not been able to cast this specimen, nor the only example of a pygidium (Reed, 1917, pl. 8, fig. 13) reproduced here. The imperfect thorax and pygidium from Pupiao figured by Reed (1917, pl. 8, fig. 14) is refigured here (Fig. 12.7). It is likely to belong to a reedocalymenine, and possibly to Reedocalymene rather than Neseuretinus . However, the pygidial pleural ribs appear to be more pronounced than is the case with the pygidium assigned with more certainty to R. unicornis by Reed (1917, pl. 8, fig.13), and its assignment must remain uncertain.