FIGURE 9. The Trichophycus ichnofabric. 1. Trichophycus venosus cross-cutting Cruziana rugosa at the base of a storm sandstone. Note scratch marks in both ichnotaxa. 2. U-shaped morphology of T. venosus. 3. High density of T. venosus at the base of a sandstone tempestite. 4 and 5. Intense bioturbation by T. venosus confined to fairweather mudstone without penetrating into the underlying sandstone tempestite. 6. Trichophycus venosus in both fairweather mudstone and storm sandstone, leading to major disturbance of the primary sedimentary fabric. 7. General view of a sandstone tempestite layer displaying several specimens of T. venosus. 8. Close-up of a specimen of T. venosus showing well-developed scratch marks. 1 and 3 are from the Humacha Member at Quebrada de Humacha. 2, 4, 5, and 6 are from the Rupasca Member at Angosto de Chucalezna. 7 and 8 are from the Acoite Formation at Quebrada de Los Colorados. Coin is 1.8 cm wide. Lens cover is 5.5 cm wide.