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The perforated shells from level II of Cueva de los Aviones (after cleaning): (1) Acanthocardia tuberculata; (2–3). Glycymeris insubrica (maximum internal diameter of the perforations: 4.2, 9.5, and 6.8 mm, respectively). See also SI Appendix, Sections I and IV, Figs. S6, S7, S15, and S16.
