The Sibley-Monroe assignment of individual species to families, and of families to orders remains controversial however. Critics maintain that while it marks a great leap forward so far as the evidence from DNA-DNA hybridisation goes, it pays insufficient attention to other forms of evidence, both molecular and on a larger scale. There is no true consensus but the broad middle-ground position is that the Sibley-Monroe classification, overall, is "about 80% correct". The key question, of course, is which 80%? Research and debate continue.
There are 9994 species on the checklist, and this page continues in several parts, which are linked to below.