Whereas during the nineteenth and most of the twentieth century, new plesiosaurs were described at a rate of three or four genera each decade, the pace suddenly picked up in the 1990s, with seventeen plesiosaurs being discovered in this period. The tempo of discovery accelerated in the early twenty-first century, with about three or four plesiosaurs being named each year. This implies that about half of the known plesiosaurs are relatively new to science, a result of a far more intense field research. Some of this is taking place away from the traditional areas, e.g. in new sites developed in New Zealand, Argentina, Chile, Norway, Japan, China and Morocco, but the locations of the more original discoveries have proven to be still productive, with important new finds in England and Germany. Some of the new genera are a renaming of already known species, which were deemed sufficiently different to warrant a separate genus name.