Author's note: these pages were written some years ago. I am not planning to update them. For a more current coverage, see the link to palaeos com Palaeos website (to which many links on these pages point to anyway. More info here

Paraphyletic Taxa

paraphyletic taxon

graphic © Darren Abbey


The Paraphyletic taxon is a group of organisms in which the most recent common ancestor of all those organisms and some, but not all, of that ancestor's descendents are included.  Paraphyletic taxa are recognised in Linnean and evolutionary systematics but not in cladistics.

Illustration: the Class Reptilia gave rise to mammals and birds, but neither mammals nor birds are included under Reptilia.

Examples:  Invertebrates, Wikipedia link Amphibia, Wikipedia link Reptilia, Dinosauria (excluding birds), Gymnosperma, etc.


graphic (top) from  external link UCMP

Polyphyletic taxon
Paraphyletic taxon
Monophyletic taxon
to Systematics
Systematics page

page history

page uploaded 13 November 1998
modified 28 November
and again 18 December