GSDs have a defined purpose, SPECIESDAB is a GSD for economically valuable fish species,[2] while FishBase focuses on fin fish regardless of their human potential for exploitation.
Attempts have been made to create GSDs for extinct species such as trilobites.
[3] A GSD can be broad in taxonomic scope, such as AlgaeBase comprehensively including algae and seagrasses from the entire planet, or narrow such as International Legume Database & Information Service, a GSD for members of a single plant family, the Fabaceae.
[4] A database restricted by geography such as Calflora focusing on California Floristic Province flowering plants and ferns is not a GSD.
The Catalogue of Life links together a number of GSDs of animals, plants, fungi, and microorganisms, such as FishBase[5] and AlgaeBase, and integrates these at a high level through a single node facilitating ease of access to global species data.