Phylogenetic relationships among major lineages of earwigs. Relationships of extant Dermaptera based on Ref. 13. Red lines are the known extinct taxa, blue lines are extant taxa, grayer lines indicate fossils possibly belonging to those groups. Different color dots show different sites with fossils. Significant characters in Dermaptera phylogeny: 1. 8th and 9th abdominal tergites in females narrowed or fused to 10th tergite; 2. Cerci unsegmented, forcipate; 3. Ocelli lost; 4. Tegminal veins lost; 5. Ovipositor reduced; 6. Posterior, ventral cervical sclerite enlarged; 7. Three pygidial subsegments fused; 8. Reduction to single penal lobe and single virga; 9. Expanded regions of anal and intercalary veins distinctly separated.