GARBAGE IN, GARBAGE OUT: THE EFFECT OF IMMATURE TAXONOMY ON DATABASE COMPILATIONS OF NORTH AMERICAN FOSSIL MAMMALS

Large databases of paleontological data are widely used now, but the analyses of these data are only as good as the quality of the original data themselves. In many cases, these databases are grossly outdated, not only because of recent taxonomic revisions that eliminate oversplit taxa from the last century, but especially (in the case of Miocene North American mammals) because the taxonomy is not yet mature; there are lots of new genera and species in the collections that have not yet been described. Checking the Paleobiology Database (PBDB) against the current taxonomy of the Palaeomerycidae, Moschidae, Rhinocerotidae, Tayassuidae, Brontotheriidae, and Merycoidodontidae shows that there are huge errors not only in invalid names and incorrect temporal and geographic ranges, but in lots of missing new taxa as well—even though the revised taxonomy of most of these families was published back in 2005-2008 or earlier. The same problems plague major groups like the Camelidae, Antilocapridae, and Proboscidea, but those taxonomic revisions are only just beginning. In short, the taxonomic and geographic data in the PBDB and older databases for most of the Miocene large land mammals of North America is so poor that any analysis of such data is premature at best. The only reliable way to use the PBDB is to already know the systematic details of any group that is the focus of a study. We should be cautious about accepting large datasets without some firsthand checking of the quality of the data.