ESTIMATING THE COMPLETENESS AND CONGRUENCE OF THE DINOSAUR FOSSIL RECORD: PHYLOGENETIC APPROACHES

The completeness and congruence of the dinosaur fossil record was investigated quantitatively for the first time, using three existing metrics: the Stratigraphic Consistency Index, the Relative Completeness Index and the Gap Excess Ratio. Two whole-Dinosauria studies were compared, along with smaller clades within the Dinosauria. Some of these clades were found to be both complete and congruent; others were poor in both respects. The whole-Dinosauria fossil record was found to be moderately good, generally showing a low degree of completeness but a high degree of congruence with the existing phylogenies. This provides circumstantial support for the relationships described. Further fossil discoveries may alter the evolutionary relationships between taxa, and may highlight further areas of inadequacy in the stratigraphic record.