Fig. 18

Pentecopterus decorahensis, metasomal tergites. a SUI 139955, tergites 9–12. b SUI 139976, tergites 8–9 showing dentate posterior margin. c SUI 139971, fragment displaying enlarged guttalate scale rows and posterior doublure with serrations. d SUI 140004, ventral cuticle with smooth articulating facet. e SUI 139974, cuticle showing central scale rows and posterior doublure. f SUI 140002, posterior margin of tergite with serrations. T9–T12 = tergites 9–12, AF = articulating facet, PD = posterior doublure, PD = posterior doublure, SR = scale row. Scale bars = 10 mm