Scientific Names: a Foundation for Biodiversity

For centuries, taxonomists have named and classified living and extinct organisms using internationally accepted rules. These scientific names, organised in a hierarchy, reflect evolutionary relationships and structure our understanding of biodiversity.

Scientific names serve as universal labels, enabling consistent communication across disciplines, regions, and generations. Knowing a species’ name gives access to everything known about it: its biology, distribution, ecological role, and importance to humanity. These names also support comparisons and biodiversity assessments across time and space. As knowledge evolves, taxonomists refine species concepts, re-evaluate earlier concepts, often describing new species and revealing that multiple names refer to the same species—known as synonyms. This means the number of scientific names exceeds the number of recognised species. While the full diversity of life is still unknown, this global effort—past and ongoing—continues to expand and sharpen the world’s taxonomic knowledge.

How New Species Are Named and Reclassified

To name a new species, a taxonomist must describe how it differs from related species, designate a type specimen —a physical reference that anchors the name, and place it within a genus and broader classification. Most species names (except for viruses) follow a binomial format: a genus name and a specific epithet. When classifications reflect evolutionary history, species are grouped with others that share a common ancestor.

As research progresses, taxonomists may revise species boundaries—splitting one species into several, merging others, or reassigning them to new genera or ranks. These taxonomic decisions reflect scientific interpretation and are separate from nomenclature. Nomenclatural codes guide how names should be handled when classifications change. For example, a species epithet can be combined with a new genus name if the classification shifts. Over time, some names—though valid under nomenclatural rules—are no longer considered accepted by taxonomists and become synonyms of the currently recognised name. This reflects the evolving nature of taxonomy and our deepening understanding of biodiversity.

Codes of Nomenclature

The naming of species is governed by international codes, each tailored to a specific group of organisms:

• Animals – International Code of Zoological Nomenclature (ICZN)
• Plants, algae, and fungi – International Code of Nomenclature for algae, fungi, and plants
• Bacteria and Archaea – International Code of Nomenclature of Prokaryotes (ICNP)
• Viruses – International Code of Virus Classification and Nomenclature (ICVCN)

These codes define how scientific names must be published and maintained. Taxonomists follow them when describing new species, ensuring names are valid, traceable, and part of the formal scientific record. The codes also include rules for correcting errors, resolving disputes, and suppressing confusing names—making nomenclature a structured, rule-based system for managing species names.

Catalogue of Life management classification

The Catalogue of Life (COL) uses a management classification maintained down to the family level, providing a stable structure for integrating datasets. This management classification uses the classification proposed by Ruggiero et al., 2015, as a starting point, which has been adapted to meet the practical needs of COL. It also allows data sources to determine the appropriate attachment points for their data within the hierarchy. This means that, in practice, that several elemets coexist: the original Ruggiero et al. classification, the COLspecific adaptations, and the specific placements chosen by data sources. Within the ChecklistBank project, this classification serves as the reference structure to ensure consistency when assembling the Catalogue, while each dataset retains metadata describing its internal classification.

Names from Molecular and Sequence-Based Data

In addition to traditional taxonomic naming based on morphology, molecular analyses of specific DNA or RNA regions have introduced new ways to recognise and group organisms. These methods generate species hypotheses (SH) or operational taxonomic units (OTUs)—clusters based on sequence similarity.

Although these groupings don’t always match formal Linnaean ranks, they are increasingly important in molecular biology, ecology, and especially in environmental DNA (eDNA) studies. SHs and OTUs help researchers study biodiversity, including organisms that remain unnamed or undescribed.

Historically, these names have not been included in authoritative taxonomic catalogues. However, due to their growing relevance, the Catalogue of Life eXtended Release (COL XR) has begun to integrate them—placing each as accurately as possible within the higher taxonomic classification.