Neontology is a part of biology that, in contrast to paleontology, deals with living (or, more generally, recent) organisms. It is the study of extant taxa (singular: extant taxon): taxa (such as species, genera and families) with members still alive, as opposed to (all) being extinct. For example: * The moose (Alces alces) is an extant species, and the dodo (Raphus cucullatus) is an extinct species. * In the group of molluscs known as the cephalopods, as of 1987 there were approximately 600 extant species and 7,500 extinct species.