Table 2. Skull measurements used.

Variables used in this study and description; see Figs. 2 and 4 for illustrations of the measurement conventions.

Abbr.	Variable	Measurement convention
BLD	Bulla diameter	Maximum diameter (in any direction) of right bulla
BOL	Basioccipital length	Maximum midsagittal length from anterior basioccipital to foramen magnum
DIL	Diastema length	Maximum distance between right I2 and M1
IOW	Interorbital width	Minimum transverse width between dorsal rims of orbits
NL	Nasal length	Maximum parasagittal length of nasal bones (i.e., orthogonal antero-posterior but not along midline)
NW	Nasal width	Maximum transverse width across posterior nasal bones
PAL	Parietal length	Maximum midsagittal length of parietal bones
SCF	Splenius capitis fossa	Maximum parasagittal length from anterior margin of M. splenius capitis insertion fossa to opisthocranion
SLD	Skull length dorsal	Maximum midsagittal length from anterior nasal bones to Opisthocranion (just dorsal to incisors) to opisthocranion
SW	Skull width	Maximum transverse width across zygomatic processes