Table 2 in Out of Xanthopygus (Coleoptera: Staphylinidae): escape from polyphyly

Table 2. List of taxonomic characters that distinguish species of Xanthopygus from Photinopygus. Numbers next to characters refers to the numbers in the data matrix. For a full list of characters and character states see Material and Methods, and for the mapping of the characters on the phylogenetic tree see Suppl. material 3.
CharactersPhotinopygusXanthopygus4. Antennae, antennomere 5(0) elongate (Figs 1A, F).(1) subquadrate (Figs 1D-E).8. Head, width in comparison to pronotum(1) subequal (Figs 1A-C).(2) wider1 (Figs 1D-E) (apomorphy).9. Head, shape, posterior margin(0) slightly extended posteriad on each side of the neck2 (Figs 1A-C) (apomorphy).(1) more or less at same level with neck border (Figs 1D-E).10. Head, eye size relative to length of head(1) medium (between 2/5 and 2/3 length of head) (Fig. 1B).(0) small (less than 2/5 length of head) (Fig. 1D) (apomorphy).15. Mandible, left, teeth structure(2) one bicuspid tooth (Fig. 1C).(1) two teeth, separated by deep emargination (Fig. 1D) (apomorphy).17. Pronotum, microsculpture(3) with sparse micropunctures (but no transverse lines visible at 70 × magnification) (apomorphy).(1) with transverse lines (seen easily at 70 × magnification)3.22. Prothorax, hypomeron, angles of superior and inferior marginal lines(0) superior and inferior line produce anterolateral angles parallel to one other (Fig. 2A).(1) superior and inferior line produce anterolateral angles not parallel to one other (Fig. 2B) (apomorphy).28. Mesothorax, mesoscutellum, dense micropunctures(0) absent (Fig. 2D) (apomorphy).(1) present (Fig. 2C).29. Mesoventrite, intercoxal process, apex(2) narrow and rounded (Fig. 2E) (apomorphy).(1) broad and rounded; or (3) broad and pointed (Fig. 2F).30. Metathorax, metepisternum, punctures(1) metepisternum covered with punctures or impunctate area less than 1/34 (Fig. 3B).(0) dorsal 1/3 of metepisterstum without punctures throughout its length (Fig. 3A) (apomorphy).32. Metathorax, metacoxae, spines on the posterior surface(0) 4 or less (Fig. 3C).(1) more than 45 (Fig. 3D).34. Metathorax, metatarsi, tarsomere 3, dorsal surface, chaetotaxy(1) tarsomeres dorsally setose (setae not restricted to marginal series) (Fig. 3F) (apomorphy).(0) developed only at margins, dorsal surface of tarsomeres glabrous (or with 1-2 setae) along midline (Fig. 3E).
1 It should be noted that head size is sexually dimorphic in Xanthopygus (but always wider than pronotum) and head size can vary drastically among specimens of the same species similarly to what has been observed in Smilax (Chatzimanolis 2016) and Triacrus dilatus (Chatzimanolis 2015a; Marlowe et al. 2015); 2 Except Ph. mirabilis and Ph. corcovadoensis (9:1); 3 Except Xa. giganteus (17:0); 4 Except Ph. mirabilis (30:0); 5 Except Xa. xanthopygus (32:0).