Testing the marine and continental fossil records

The fossil record of continental vertebrates is as good as that of echinoderms at the family level, as shown by tests of the match of cladistic and stratigraphic data and of relative completeness. If echinoderms and vertebrates are typical of their environments, the continental fossil record is not worse than the marine, despite the fact that, at a local level, fossils are usually more abundant in marine sequences than in continental successions. The explanation of this paradox may be that vertebrates have attracted more intensive study than echinoderms, and thus the level of knowledge of their fossil record is some decades ahead of that of echinoderms. This finding validates the use of different kinds of fossil data in broad-scale phylogenetic studies.