Table 2. Possible categories and classes for recursive partition analysis.

			Morphologial categories
		Compacta
Taxon	Extensive trabeculae	Layer thickness	Density	Large struts	Surface vessels	Head shape	Neck muscles
Stegoceras	yes	thick	dense	struts	yes	domed	broad
Ovibos	yes	intermed.	dense	struts	yes	domed	broad
Giraffa	no	thick	dense	struts	no	spiked	narrow
Lama	no	thin	sparse	no struts	no	flat	narrow
Tayassu	no	thin	sparse	no struts	no	flat	narrow
Antilocapra	no	thin	dense	no struts	no	flat	moderate
Ovis	yes	intermed.	dense	struts	yes	domed	broad
Synceras	yes	intermed.	dense	struts	yes	domed	broad
Buceras	yes	thick	dense	struts	yes	domed	broad
Equus	no	thin	sparse	no struts	no	flat	narrow
Cephalophus	yes	thick	dense	struts	no	domed	broad

Biomechanical categories can be included in RPA, but missing data gives more ambiguous results. Specific behavior and Agonism) are alternate choices for behavioral class. For layer thickness, “intermed" refers to intermediate compacta thickness. “Thick" for the giraffe refers to compact bone of the ossicones.