Fig. 10. Schematic cross-section of stridulatory file and scraper (based on anatomy of Arachnoscelis n. sp.) showing hypothetical mechanism of stridulation in extreme-frequency singers. (A) Different degrees of deformation the scraper may undergo while pausing behind a tooth in advance of pulse production. (B) With enough bending, the scraper's shape allows release, and it springs forward along a series of teeth lodging at the last tooth of the series (blue asterisk). Pulse-driven oscillations (one per tooth) indicated with broken lines, contacted teeth with red asterisks. Decay oscillations indicated by dotted red arrows.