Illaenus sp. 3

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 : 348

Illaenus sp. 3

Fig. 14.12

1917 Illaenus cf. esmarki Schloetheim; Reed pl. 7, fig. 14; pl. 8, figs 1,2.

Material. Cranidium, Fig. 14.12 ( Reed, 1917, pl. 8, figs 1,2), GSI 11905; cranidium ( Reed, 1917, pl. 7, fig. 14), GSI 11903. Both specimens from Shihtien Formation (Darriwilian) at Pupiao, western Yunnan.

Remarks. We refigure one of the two cranidia figured by Reed (1917). He figured a detail of an external mould showing strong terrace ridges on the front of the cephalic shield, and this feature is suggested also on the internal surface. There are few other features, and a critical determination is impossible without further material.

Figures

FIGURE 14. (1–7) Parillaenus liluensis (Reed) from the Li-Lu formation (Katian), Lilu, northern Shan State, Myanmar. 1. Cranidium (original of Reed 1915, pl. 7, fig. 10), GSI 11541. 2. Cranidium (original of Reed 1915, pl. 7, fig. 12), GSI 11543. 3. Cranidium (refigured from Reed 1915, pl. 7, fig. 4), GSI 11536. 4. Pygidium and partial thorax (refigured from reed 1915 Pl. 7, fig. 7), GSI 11538. 5. Complete specimen (refigured from Reed 1915, pl. 7, fig. 5), GSI 11537. 6. Complete specimen (original of Reed 1915, pl. 7, fig. 5), GSI 11537. 7. Hypostome (refigured from Reed 1915, pl. 7, fig. 6), GSI 11537. (8, 11) Illaenus sp. 2 (Reed) from the Shihtien Formation (Darriwilian, Banpo Village, Shidian County, Baoshan Prefecture, western Yunnan, China. 8. Pygidium (original of Reed 1917, pl. 7, fig. 12), GSI 11901. 11. Cranidium (original of Reed 1917, pl. 7, fig. 13), GSI 11902. (9, 10) Illaenus sp. 1 (Reed) from the Hwe Mawng Beds (uppermost Katian) and Li-Lu Formation (Katian), northern Shan State, Myanmar. 9. Cranidium (original of Reed 1915, pl. 7, fig. 8), GSI 11539, Hwe Mawng. 10. Cranidium (original of Reed 1915, pl. 7, fig. 9), GSI 11540, Mân-ngai. (12) Illaenus sp. 3 (Reed), Cranidium (original of Reed 1917, pl. 8, fig. 1), GSI 11905, Shihtien Formation (Darriwilian), Pupiao, Baoshan Prefecture, western Yunnan, China. Scale bar = 1 mm for 1, 2, 7; = 5 mm for 3, 8–12; = 2 mm for 4–6.