Table 1. Description of the 23 cranial measurements used in this study.

See Fig. 1 for diagram. Modified from Dodson (1975a).

#	Description of variable
1	Skull width at posterior border of external nares
2	Skull width at 4th maxillary tooth
3	Skull width at anterior border of orbit
4	Skull width at posterior border of quadratojugals
5	Skull width across exoccipitals
6	Skull length from tip of snout to quadrates
7	Skull length from tip of snout to anterior border of orbits
8	Skull length from posterior border of orbit to external condyle of quadrate
9	Orbit length
10	Orbit width
11	Orbit separation
12	Lateral temporal fenestra length
13	Lateral temporal fenestra height
14	Maxilla length
15	Palatal fenestra width
16	Distance from the posterolateral corner of the pterygoid to the medial condyle of quadrate
17	Height of skull from pterygoid process to dorsal surface of skull, perpendicular to long axis
18	Maximum depth of jaw
19	External mandibular fenestra length
20	External mandibular fenestra width
21	Retroarticular process length, from crest of ridge posterior to articular cotyles to tip of process
22	Palatal fenestra length
23	Foramen magnum width