Definition of paraphyletic in US English:



  • (of a group of organisms) descended from a common evolutionary ancestor or ancestral group, but not including all the descendant groups.

    • ‘To represent this, we have used multiple lines drawn to paraphyletic groups in the cladogram above.’
    • ‘These taxa together form a paraphyletic group at the base of the clade of biramous arthropods.’
    • ‘In fact, it is possible that the group is paraphyletic; the last common ancestor of all polymerid trilobites may also have been ancestral to the agnostids as well.’
    • ‘However, each tribe individually is either paraphyletic or polyphyletic with respect to most recent songbird classifications.’
    • ‘It now seems likely that the first two of these groups are paraphyletic; that is, they contain some but not all descendants of a common ancestor.’