Species inquirenda

In biological classification, a species inquirenda is a species of doubtful identity requiring further investigation. The use of the term in English-language biological literature dates back to at least the early nineteenth century.

The term taxon inquirendum is broader in meaning and refers to an incompletely defined taxon of which the taxonomic validity is uncertain or disputed by different experts or is impossible to identify the taxon. Further characterization is required.

See also

• Glossary of scientific naming
• Candidatus, a proposed taxa based on incomplete evidence
• incertae sedis, a taxon of uncertain position in a classification
• nomen dubium, a name of unknown or doubtful application
• Open nomenclature, a system of notations used in taxonomy to indicate a taxonomist's judgement about taxon affinities