Q: Why do the TYGS results sometimes include species whose names are not validly published?
The TYGS is showing such matches because it may be important for any taxonomist to be aware of all closely related species or subspecies even if their names are not (yet) validly published. Since several criteria have to be met before a new species name is validly published (see details on LPSN page), the entire process might take some time. For example, it can well be that a novel species or subspecies name was already proposed in an effective publication but has still not been announced in a Validation List. In theory, a second team might now start working on the description of the same taxon, resulting in redundant work. That is, if your novel strain is placed in the same species or subspecies cluster as a species or subspecies with a not (yet) validly published name, we recommend to get in touch with its authors. An effective publication may be available and the valid publication of the name may be imminent. And even in the case of a low probability of a forthcoming validation it is often worth reporting phylogenetically close relationships to taxa that lack a validly published name. Their names occur in databases anyway and their analyses may yield valuable information.