| Comments |
P.54 right column top paragraph: "Potentially valuable comparisons of extinction magnitude could come from assessing modern taxonomic groups that are also known from exceptionally good fossil records. The best fossil records are for near-shore marine invertebrates like gastropods, bivalves and corals, and temperate terrestrial mammals, with good information also available for Holocene Pacific Island birds (refs 2, 33, 35, 42, 44 primary source 43). However, better knowledge of understudied modern taxa is critically important for developing common metrics for modern and fossil groups. For example, some 49% of bivalves went extinct during the end-Cretaceous event (primary source), but only 1% of today’s species have even been assessed (ref 6), making meaningful comparison difficult." |