Appendix. List of characters (modified from Sidor and Welman 2003) used to construct the cladograms in Figure 10.

1. Premaxillary vomerine processes: short (0), long, bounding vomer in between and approaching level of upper canine posteriorly (1).

2. Length of dorsal process of premaxillae: short (0), or long, reaching to level posterior to that of upper canine (1).

3. Septomaxilla contained within external naris (0) or escaping to facial exposure (1).

4. Lateral surface of lacrimal bearing one or more deep fossae: absent (0), present (1).

5. Maxilla contacting prefrontal: absent (0), present (1).

6. Shape of dorsal surface of nasals: flat (0), with narrow, ridge-like eminence (1), with transversely expanded median boss (2).

7. Supraorbital margin thin (0), moderately thickened (1), or greatly thickened into boss (2).

8. Boss at posterodorsal margin of orbit, near origin of postorbital bar: absent (0), present (1).

9. Ventrolateral surface of zygomatic arch and suborbital bar: smooth (0), or with two ventrolaterally projecting knobs (1).

10. Squamosal thickened on ventral surface of zygomatic arch lateral to position of quadrate: absent (0), present (1).

11. Posterior portion of zygomatic arch bent strongly ventrally: absent (0), present (1).

12. Squamosal ‘‘horns’’ directed posterodorsally from skull roof: absent (0), present (1).

13. Squamosal thickened along its posterior border with tabular: absent (0), present and well developed (1).

14. Shape of dorsal surface of frontals: flat (0), with low ridge (1), or with tall, thickened ridge (2).

15. Length of posterior process of postorbital: stopping above LTF (0), descending onto posterior margin of LTF (1).

16. Circum-pineal parietal shape: flat (0), low and diffuse swelling (1), or forming well-defined chimney (2).

17. Preparietal: absent (0), present (1).

18. Supratemporal: present (0), absent (1).

19. Interchoanal portion of vomer broad (0) or forming median ridge (1) where it meets post-choanal portion.

20. Medial edge of pterygoid basicranial ramus having parasagittal ventral ridge: absent (0), present (1).

21. Row of teeth on transverse flange of pterygoid: present (0), absent (1).

22. Ectopterygoid teeth: present (0), absent (1).

23. Palatine dentition broadly distributed (0), or restricted to small area (1) on palate.

24. Position of transverse flange of pterygoid: under posterior half of orbit (0), under anterior half of orbit (1), or preorbital (2).

25. Basicranial rami of pterygoids broadly separated (0), narrowly separated with median trough formed (1), or broadly contacting anterior to basicranium (2).

26. Forward rotation of occiput: none (0), moderate (5vertical) (1).

27. Stapedial foramen: present (0), absent (1).

28. Exoccipitals meeting (0) or separated (1) on dorsal surface of occipital condyle.

29. Shape of postparietal: wider than tall (0), approximately square (1), or taller than wide (2).

30. Dentary-angular suture shape: diagonal (0), or posterior margin of dentary deeply incised (1).

31. Angular with pattern of ridges and fossae on its lateral surface: absent (0), present (1).

32. Articular dorsal process: absent (0), present (1).

33. Dorsal edge of surangular just posterior to dentary with laterally projecting ridge: absent (0), or present (1).

34. Upper incisors large, approaching size of caniniform tooth (0) or much smaller than caniniforms (1).

35. Upper and lower incisors intermesh: absent (0), present in anterior incisors (1), present in all incisors (2).

36. Lower canine fiting into choana (0), or into fossa roofed by premaxilla and maxilla (1).

37. Number of upper postcanines: 12 or more (0), fewer than 12 (1).