# Figures

**Figure 3.10** Clade–stratigraphic metrics. Calculation of the three congruence metrics for age versus clade comparisons. SCI is the ratio of consistent to inconsistent nodes in a cladogram. RCI is RCI = 1(SMIG/SSRL), where MIG is minimum
implied gap, or ghost range, and SRL is standard range length, the known fossil record. GER is GER = 1(MIG - G_{min})/(G_{max}
- G_{min}), where G_{min} is the minimum possible sum of ghost ranges and G_{max} the maximum, for any given distribution of
origination dates. (a) The observed tree with SCI calculated according to the distribution of ranges in (b). (b) The observed
tree and observed distribution of stratigraphic range data, yielding an RCI of 66.0%. GER is derived from Gmin and G_{max}
values calculated in (c) and (d). (c) The stratigraphic ranges from (b) rearranged on a pectinate tree to yield the smallest
possible MIG or Gmin. (d) The stratigraphic ranges from (b) rearranged on a pectinate tree to yield the largest possible MIG
or Gmax. (Based on Benton et al. 2000.)