Classification Providers

The information on EOL is organized using hierarchical classifications of taxa (groups of organisms) from a number of different classification providers.  You can explore these hierarchies in the Names tab of EOL taxon pages.  Many visitors would expect to see a single classification of life on EOL.  However, we are still far from having a classification scheme that is universally accepted. 

Biologists all over the world are studying the genetic relationships between organisms in order to determine each species' place in the hierarchy of life.  While this research is underway, there will be differences in opinion on how to best classify each group.  Therefore, we present our visitors with a number of alternatives.  Each of the hierarchies below is supported by a community of scientists, and all of them feature relationships that are controversial or unresolved.  In addition to these community vetted hierarchies, you will also find a variety of other, unvetted hierarchies in the Names tab of most EOL pages.  These hierarchies often help to bridge gaps in EOL coverage for groups that are poorly studied and not well represented in community maintained nomenclators.

By default, the scientific name you see as the title of an EOL page and the hierarchy displayed in the classification browser in the Overview tab are derived from one of the community vetted classifications. Names and hierarchies from unvetted classifications are only used as page titles and browsing hierarchies if a given taxon is not represented in any vetted classification. However, EOL curators can change page titles and browsing hierarchies for individual taxon pages by selecting a preferred classification from the hierarchies featured in the Names tab of an EOL page.

We invite the scientific community to submit additional vetted hierarchies to improve EOL's coverage of current systematic hypotheses.  Please contact the Species Pages Working Group for additional information.

Current EOL classification providers include

AlgaeBase is a database of information on algae that includes terrestrial, marine and freshwater organisms. At present, the data for the marine algae, particularly seaweeds, are the most complete. For convenience, we have included the sea-grasses, even though they are flowering plants. 

AntWeb is generally recognized as the most advanced biodiversity information system at species level dedicated to ants. Altogether, its acceptance by the ant research community, the number of participating remote curators that maintain the site, number of pictures, simplicity of web interface, and completeness of species, make AntWeb the premier reference for dissemination of data, information, and knowledge on ants. AntWeb is serving information on tens of thousands of ant species through the EOL.

Avibase is an extensive database information system about all birds of the world, containing over 6 million records about 10,000 species and 22,000 subspecies of birds, including distribution information, taxonomy, synonyms in several languages and more. This site is managed by Denis Lepage and hosted by Bird Studies Canada, the Canadian copartner of Birdlife International. Avibase has been a work in progress since 1992 and it is offered as a free service to the bird-watching and scientific community. In addition to links, Avibase helped us install Gill, F & D Donsker (Eds). 2012. IOC World Bird Names (v 3.1). Available at as of 2 May 2012.  More bird classifications are likely to follow

Clements Checklist
The Cornell Laboratory of Ornithology uses science to understand the world, to find new ways to make conservation work, and to involve people who share our passion. For now the primary contribution is the Clements Checklist. This is the most established resource on the taxonomy and biogeography of birds for the birding community, The Clements Checklist is the official world checklist of the American Birding Association (ABA) and is used as the authoritative reference in the birding competitions and listing activities of this preeminent North American organization for serious birders. 

Catalogue of Life
The Catalogue of Life Partnership (CoLP) is an informal partnership dedicated to creating an index of the world’s organisms, called the Catalogue of Life (CoL). The CoL provides different forms of access to an integrated, quality, maintained, comprehensive consensus species checklist and taxonomic hierarchy, presently covering more than one million species, and intended to cover all know species in the near future. The Annual Checklist EOL uses contains substantial contributions of taxonomic expertise from more than fifty organizations around the world, integrated into a single work by the ongoing work of the CoLP partners. 

Catalogue of Life China
The Species 2000 China Node is a regional hub of the international program-Species 2000 program, it was proposed to establish on February 7, 2006 by the Species 2000 Secretariat and is launched up on October 20, 2006. The Biodiversity Committee of Chinese Academy of Sciences (BC-CAS), cooperated with other partner organizations, supports and supervises the establishment of the Species 2000 China Node. The goal of the Species 2000 China Node project is to collect and verify the taxonomic information of all species (plants, animals and microorganisms) distributed in China, provide a validated checklist, the Catalogue of Life China, to all users in the world.

A compendium of all the terrestrial and freshwater flatworms (Tricladida).

FishBase is a global information system with all you ever wanted to know about fishes. FishBase is a relational database with information to cater to different professionals such as research scientists, fisheries managers, zoologists and many more. The FishBase Website contains data on practically every fish species known to science. The project was developed at the WorldFish Center in collaboration with the Food and Agriculture Organization of the United Nations and many other partners, and with support from the European Commission. FishBase is serving information on more than 30,000 fish species through EOL.

Index Fungorum
The Index Fungorum, the global fungal nomenclator coordinated and supported by the Index Fungorum Partnership (CABI, CBS, Landcare Research-NZ), contains names of fungi (including yeasts, lichens, chromistan fungal analogues, protozoan fungal analogues and fossil forms) at all ranks.

IRMNG - Interim Register of Marine and Nonmarine Genera
The Interim Register of Marine and Nonmarine Genera (IRMNG) is a project of OBIS Australia designed to assist in the provision of marine species data to OBIS, by permitting the discrimination of marine from nonmarine (and extant from fossil) species records on the basis of the genus name portion of their scientific name (normally, genus + species, or genus + species + infraspecies if applicable). The aim of the project is to (a) assemble as complete a list as possible of the estimated 150,000 extant and 50,000 fossil generic names in current use, plus their possible further 250,000-300,000 synonyms, and (b) flag as many of these as is possible with their marine/nonmarine, and extant/fossil, status. Relevant species lists are also being attached to the "correct" instances of genus names as available.

The Integrated Taxonomic Information System (ITIS) is a partnership of federal agencies and other organizations from the United States, Canada, and Mexico, with data stewards and experts from around the world (see The ITIS database is an automated reference of scientific and common names of biota of interest to North America . It contains more than 600,000 scientific and common names in all kingdoms, and is accessible via the World Wide Web in English, French, Spanish, and Portuguese ( ITIS is part of the US National Biological Information Infrastructure (

International Union for Conservation of Nature (IUCN) helps the world find pragmatic solutions to our most pressing environment and development challenges. IUCN supports scientific research; manages field projects all over the world; and brings governments, non-government organizations, United Nations agencies, companies and local communities together to develop and implement policy, laws and best practice. EOL partnered with the IUCN to indicate status of each species according to the Red List of Threatened Species.

Metalmark Moths of the World
Metalmark moths (Lepidoptera: Choreutidae) are a poorly known, mostly tropical family of microlepidopterans. The Metalmark Moths of the World LifeDesk provides species pages and an updated classification for the group.

As a U.S. national resource for molecular biology information, NCBI's mission is to develop new information technologies to aid in the understanding of fundamental molecular and genetic processes that control health and disease. The NCBI taxonomy database contains the names of all organisms that are represented in the genetic databases with at least one nucleotide or protein sequence.

Rotifers of the World
This project aims at synthesizing and sharing online authoritative data about nomenclature, taxonomy, geographic distribution, ecology, collection specimens, and bibliography for all 4000+ nominal taxa of Rotifera that were described since the start of zoological nomenclature.

South African Vertebrates
SANBI (the South African National Biodiversity Institute) was established in terms of the National Biodiversity Management Act of South Africa. SANBI succeeds the National Botanical Institute, which together with its predecessor, has a history of more than a century of botanical exploration and research in South and southern Africa. SANBI has a legal mandate that includes the co-ordination and promotion of taxonomy, monitoring and reporting on the status of South Africa's biodiversity, as well as the collection, generation, processing, co-ordination and dissemination of information about biodiversity.

The Paleobiology Database
The Paleobiology Database is a public resource for the global scientific community. It has been organized and operated by a multi-disciplinary, multi-institutional, international group of paleobiological researchers. Its purpose is to provide global, collection-based occurrence and taxonomic data for marine and terrestrial animals and plants of any geological age, as well as web-based software for statistical analysis of the data. The project's wider, long-term goal is to encourage collaborative efforts to answer large-scale paleobiological questions by developing a useful database infrastructure and bringing together large data sets.

The Reptile Database 
This database provides information on the classification of all living reptiles by listing all species and their pertinent higher taxa. The database therefore covers all living snakes, lizards, turtles, amphisbaenians, tuataras, and crocodiles. It is a source of taxonomic data, thus providing primarily (scientific) names, synonyms, distributions and related data. The database is currently supported by the Systematics working group of the German Herpetological Society (DGHT)

The aim of a World Register of Marine Species (WoRMS) is to provide an authoritative and comprehensive list of names of marine organisms, including information on synonymy. While highest priority goes to valid names, other names in use are included so that this register can serve as a guide to interpret taxonomic literature.