Species, the fundamental units of taxonomy, have to be described according to the rules outlined in the ICZN-Code. However, the current requirements for species description need to be adjusted to modern demands. This can be achieved by implementing:
1.) Species diagnoses that are based on differences in nucleic acid sequences, allowing to distinguish new species from their closest relatives; genetic data need to be supplemented by phenotypic data to ensure the integration into existing reference systems. The quest for molecular data should be manifested.
2.) A provisional status should be accepted for partially characterised species (“candidate species” or “operational taxonomic units”).
For the time being, I would advise taxonomists against describing new species or making species-level revisions until a universally applicable species-rank delimitation method is agreed upon.
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