PLATE 7. 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 7. 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, 2, 3, 5. Cephalon and thoracic segments, SUI 147552, dorsal, ventral, anterior, and left lateral views, x9 (MME 84.0 m). 4, 7. Cranidium, SUI 147553, left lateral and dorsal views, x7.5 (HC6 107.5 m). 6, 9, 10. Cranidium, SUI 147554, dorsal, anterior, and right lateral views, x10 (MME 84.0 m). 8, 11, 12. Cranidium, SUI 147555, anterior, right lateral, and dorsal views, x12 (MME 84.0 m). 13, 15, 17. Right librigena, SUI 147556, internal, ventrolateral, and external views, x10 (AAA 79.5 m). 14, 18. Left librigena, SUI 147557, internal and external views, x12 (MME 84.0 m). 16. Left librigena, SUI 147558, external view, x12 (AAA 79.5 m).