The haptophytes, classified either as the Prymnesiophyta (named for Prymnesium) or Haptophyta, are a division of algae. The names Haptophyceae or Prymnesiophyceae are sometimes used instead. This ending implies classification at the class rank rather than as a division. Although the phylogenetics of this group has become much better understood in recent years, there remains some dispute over which rank is most appropriate.