Regional support within the overall solution 54 



Bootstrap analysis 54 



Successive approximations 58 



Support analysis 58 



Overall conclusions 58 



Comparative tools 66 



Constraint analysis 66 



Outgroup constraints 66 



Internal constraints 71 



Overall conclusions - possible effects of polymorphic data 76 



Missing taxa 77 



Unweighted solution 81 



Condensed analysis 83 



Character analysis 85 



Snout 86 



Orbit and zygomatic arch 95 



Palate and ventral side of snout 108 



Basicranial region 115 



Bony tentorium and bony falx 133 



Dorsal braincase 135 



Teeth 137 



Mandible 147 



Forelimb 148 



Pelvis 154 



Hind Limb 158 



Miscellaneous 162 



Summary 165 



Discussion and conclusions 175 



Summary of results 175 



Potential sources of error 177 



Taxonomic implications 180 



Biogeography and fossil evidence 181 



Future directions 185 



Abstract 187 



Literature cited 188 



Appendices: 198 



A: Specimen list 198 



B: List of characters 202 



C: Character matrix 210 



D: Branch lengths and linkages 212 



E: Apomorphy lists (unweighted) 214 



F: Character diagnostics (unweighted) 252 



