Table 2.

Subsampling methods used in this study

Method	Items drawn	Weighting	Assumption	References
Rarefaction	O	O	O proportional to N	13, 39
UW	L	L	O independent of N	40
OW	L	O	O proportional to N	10, 11
O2W	L	O2	O2 proportional to N	31

Each algorithm proceeds by drawing items until a quota is reached, with the quota being based on the weighting variable. “Assumption” is the assumed relationship between presence-absence data for collections used in the analysis and counts of individual fossil specimens within these collections. L, number of lists; N, number of specimens in a fossil collection; O, number of distinct genus occurrences.