Illaenus sp. 1

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 : 346

Illaenus sp. 1 .

Figs 14.9 , 10

1915 Illaenus aff. portlocki Reed, pl. 7, figs 8,9.

Material. Pygidium from Hwe Maung Beds (uppermost Katian) at Hwe Maung, Fig. 14.9 ( Reed, 1915, pl. 7, fig. 8), GSI 11539; cranidium from Upper Naungkangyi Beds at Man Ngai, Fig. 14.10 ( Reed, 1915, pl. 7, fig. 9), GSI 11540.

Remarks. These two sclerites may not belong to the same species. The internal mould of the cranidium shows evidence of carrying raised transverse ridges anteriorly which may have been strong on the dorsal surface. The same feature is seen on Illaenus sp. 3 from Yunnan, but not enough is known of either species to prove they are the same species.

Figures

FIGURE 10. (1, 2) Lonchodamas? sp. (Reed) from the Li-Lu Formation (Katian), Lilu, northern Shan State, Myanmar. 1a, b. Pygidium (original of Reed 1915, pl. 5, fig. 6), GSI 11508, original and retrodeformation. 2. Cranidium (refigured from Reed 1915, pl. 5, fig. 5), GSI 11507. (3, 6) Lonchodamas shanensis (Reed) from the Hwe Mawng Beds (uppermost Katian), northern Shan State, Myanmar. 3. Pygidium (original of Reed 1915, pl. 5, fig. 3), GSI 11505, Hwe-hok. 6. Cranidium (original of Reed 1915, pl. 5, fig. 2), GSI 11504, Mong Ha. (4) Dionide hybrida (Reed), Cephalon (original of Reed 1915, pl. 5, fig. 7), GSI 11509, Hwe Mawng Beds (uppermost Katian), Hwe-hok, northern Shan State, Myanmar. (5, 8) Ovalocephalus? sp. indet. (Reed) from the Li-Lu Formation (Katian), Mân-ngai, northern part of Shan State, Myanmar. 5. Cranidium (original of Reed 1915, pl. 8, fig. 17), GSI 11563. 8. Thorax (original of Reed 1915, pl. 8, fig. 21), GSI 11567. (7) Pliomerina martellii (Reed), Cranidium (original of Reed 1917, pl. 8, fig. 15), GSI 11915, Shihtien Formation (Darriwilian), Pupiao, Baoshan Prefecture, western Yunnan, China. (9) Prionocheilus liluensis (Reed), Cranidium (original of Reed 1915, pl. 8 figs 6 and 7), GSI 11554, Li-Lu Formation (Katian), Lilu, northern Shan State, Myanmar. (10, 13) Ovalocephalus sp. (Reed) from the Li-Lu Formation (Katian), Lilu, northern Shan State, Myanmar. 10. Pygidium (original of Reed 1915, pl. 8, fig. 9), GSI 11556. 13. Cephalon; not previously figured; no GSI catalogue number. (11, 12) “Calymene” oldhami (Reed) from Lower Naungkangyi Beds (probable Darriwilian), Mâ Shio, northern Shan State, Myanmar. 11. Cephalon and thorax (original of Reed 1915, pl. 8, fig. 11), GSI 11558. 12. Cephalon and partial thorax (original of Reed 1915, pl. 8, fig. 10), GSI 11557. Scale bars = 2 mm for 1–3, 6, 8–13; = 5 mm for 4, 5; = 1 mm for 7.

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.