| Comments |
Tree of relationships of the key genome model organisms showing minimum (bold) and maximum (roman) fossil-based dates for each branching point. The pattern of relationships is based on a consensus of current views. The minimum age constraints are based on the oldest fossil confidently assigned to either of the two sister groups that arise from each branching point. The maximum age constraint is based on bracketing (maximum ages of sister groups) and bounding (age of an underlying suitable fossiliferous formation that lacks a fossil of the clade). Full justification for each minimum and maximum fossil-based age constraint is available at link |