sentences:  , the Catalogue lists 1,837,565 of the world's 2.2m extant species known to taxonomists on the planet at present time.The Catalogue of Life employs a simple data structure to provide information on synonymy, grouping within a taxonomic hierarchy, common names, distribution and ecological environment.The Catalogue provides a dynamic edition, which is updated monthly (and in which data can change without tracking of those changes) and an Annual Checklist, which provides a dated, verifiable reference for the usage of names and associated data.