Table 2.

Phylogenetic studies from which characters were selected

Reference	Taxonomic group	No. of taxa	No. of characters
Hill (31)	Amniotes	80	365
Skutschas and Gubin (32)	Amphibians	22	69
Nesbitt et al. (33)	Birds	22	107
Coates and Sequeira (30)	Cartilaginous fishes	23	86
Chakrabarty (34)	Cichlid fishes	41	89
O’Leary et al. (35)	Mammals	84	4541
Conrad (36)	Squamate reptiles	223	363