26. Postorbital-squamosal contact: postorbital forms a tapering finger-like squamosal process the overlaps the squamosal (0), this process develops a bifurcate tip (1). McDonald et al. (2010) proposed that this process might be coded in three ways: “blunt,” “pointed,” or “bifurcate.” However, there is variation in this structure as it is illustrated in skull reconstructions, which makes the distinction between “blunt” and “pointed” one that is potentially subjective and risks misinterpretation.
27. Foramen magnum dorsal margin: supraoccipital in dorsal margin (0), supraoccipital excluded from dorsal margin by exoccipitals (1).
28. Foramen magnum ventral margin: basioccipital in ventral margin (0), basioccipital excluded from ventral margin by the exoccipitals (1). This character, though commonly used and perhaps of more value at a coarser scale (e.g., across higher-level taxonomic groupings), is often difficult to assess reliably (within individual taxa), and may vary ontogenetically and be subject by taphonomic influence.
29. Paroccipital wing shape: horizontal and dorsoventrally expanded distally (0), pendant distal tip (1).
30. Basipterygoid process orientation: anteroventral (0), posterolateral (1).
32. Predentary shape (in plan view): subtriangular (0), arcuate (1), broad and subrectangular (2).
33. Predentary ventral lobe: median tab sometimes notched in the midline (0), deeply incised in the midline and with strongly bifurcate lobes (1).
34. Predentary rostral surface: smooth (0); bearing a pair of oblique grooves, one on either side of midline (1), midline groove (2).
35. Mandibular diastema (the gap between the posterior end of the predentary and the first dentary alveolus): absent (0), present (1), greater than three crown widths (2). Difficult to assess in instances in which the predentary is not articulated with the dentary and/or when the anterior part of the dentary is not well preserved.
36. Dentary ramus shape in lateral view: straight (0), arched along its ventral edge (1).
38. Dentary coronoid process profile: axis of coronoid oblique (posterodorsal orientation) (0), perpendicular (1), anteriorly inclined (2).
39. Dentary coronoid process shape: dorsal tip unexpanded (0), expanded (1).
40. Dentary coronoid process position: laterally offset and dentition [alveoli] curves laterally into its base (0), posterior dentition extends medial to the middle of the coronoid process (1), posterior dentition extends posterior to the coronoid process (2).
41. Surangular foramen: present (0), absent (1).
42. Surangular-angular suture: obliquely inclined (0), horizontal (1). Difficult to score faithfully because this feature may be based upon skull reconstructions which may, or may not, be accurate in this area.
43. Angular: lateral exposure. Visible laterally (0), not visible (contact with surangular is positioned ventrally or medially) (1).
44. Replacement crowns present: one (0), two (1), three or more (2).
45. Wear facet distribution on dentary and maxillary crowns: irregular and discontinuous distribution on individual crowns (0), wear facets continuous across adjacent crowns, producing a uniformly narrow cutting/grinding surface (1), the oldest and successional crowns contribute to the wear surface to varying degrees to produce a transversely broader cutting/grinding occlusal (2).
46. Relative crown width: maxillary crowns equal in width to dentary crowns (0), narrower than dentary crowns (1), equal in width to dentary crowns, but “miniaturized” (2).
47. Enamel surface distribution on tooth crowns: equally distributed on both sides of crown (0), asymmetrical distribution, thicker on one surface of the crown (1), enamel is restricted to one side of the crown (2).
48. Marginal denticle shape: simple cones (0), tongue-shaped (1), curved ledges with mammillae (2), absent, or reduced to small irregular papillae (3).
50. Dentary tooth curvature of long axis: the root–crown axis of the tooth is straight (0), the long axis of the tooth is bowed lingually so that the occlusal portion of the crown becomes directed labiodorsally (1).
51. Dentary teeth, crown shape in lingual view: simple, symmetrical leaf-shaped profile (0), broad, shield-like (1), in unworn examples occlusal margin forms a distinct shoulder mesially (2), mesiodistally compressed and diamond shaped (3).
52. Dentary teeth, presence of oblique, thickened ledges at the base of the enamelled lingual face of the crown: absent (0), present (1).
53. Dentary teeth, primary ridge: absent (0), median position (1), distally offset (2).
54. Dentary teeth, ridge pattern: simple median swelling (0), prominent primary ridge with variable number of parallel subsidiary ridges (1), parallel primary and secondary ridge divide crown face into three zones (2), primary ridge alone (3).
55. Dentary teeth, relative size in mandible: large and shield shaped (0), miniaturized (1).
57. Maxillary teeth shape 1: equal width to dentary crowns (0), narrower and more lanceolate than opposing dentary crowns (1), lanceolate but equal in width to dentary crowns (2).
58. Maxillary teeth shape 2: Root–crown long axis of the tooth straight (0); long axis bowed, convex labially (1).
59. Maxillary teeth, labial ridges 1: simple median swelling (0), very prominent primary ridge (1), several subsidiary ridges and no obvious primary ridge (2).
60. Maxillary teeth, labial ridges 2: simple medial swelling (0), array of primary, secondary, and subsidiary ridges (1), single median primary ridge with no other ridges present (2).
61. Axis vertebra. Neural spine shape: low and sloping (0), tall and expanded (1).
62. Cervical vertebrae. Centrum articular surfaces: amphiplatyan (0), opisthocoelous (1).
63. Dorsal vertebrae. Neural spine shape: low and rectangular (0), tall and narrow (1). Extremely tall, relative to the anteroposterior dimension of spine (2). Dubious. Biomechanical: small animals have short neural spines. Only two taxa, Ouranosaurus and Hypselospinus, have extremely elongate neural spines—i.e., probable homoplasy.
64. Epaxial ossified tendons: arranged in linear bundles (0), form a layered lattice against the neural spines (1). Dubious: reflects the accommodation space available: taller spines enable a lattice-like arrange of tendons to exist.
65. Ossified tendons form a posterior caudal sheath: absent (0), present (1). Rarely preserved, and where a sheath of tendons is known, its occurrence seems to be restricted to basal clypeodontans and may be plesiomorphic within cerapodans.
