PLATE 8. Tesselacauda depressa Ross, 1951, from Section MME 84.0 m in Revision of the Early Ordovician (late Tremadocian; Stairsian) cheirurid trilobite Tesselacauda Ross, with species from the Great Basin, western USA

PLATE 8. Tesselacauda depressa Ross, 1951, from Section MME 84.0 m, Middle Mountain, AAA 79.5 m, northern House Range, both Fillmore Formation, Ibex area, Millard County, western Utah, USA, and HC6 107.5 m, Garden City Formation, west side of Hillyard Canyon, Bear River Range, Franklin County, Idaho, USA (all upper Tremadocian; Stairsian; Bearriverops deltaensis Zone). 1–4, 8. Hypostome, SUI 147559, right lateral, posterior, ventral, anterior, and dorsal views, x12 (HC6 107.5 m). 5, 7, 11. Pygidium, SUI 147560, dorsal, posterior, and left lateral views, x12 (MME 84.0 m). 6, 9, 12, 14, 15. Pygidium and thoracic segment, SUI 147561, dorsal, posterior, ventral, right lateral, and anterior views, x12 (MME 84.0 m). 10, 13, 16, 17, 19. Pygidium, SUI 147562, dorsal, posterior, ventral, right lateral, and anterior views, x15 (AAA 79.5 m). 18, 20, 21. Pygidium, SUI 147563, dorsal, left lateral, and posterior views, x15 (AAA 79.5 m).