phylogentic terms

1.paraphyletic -- Term applied to a group of organisms which includes the most recent common ancestor of all of its members, but not all of the descendants of that most recent common ancestor

-Paraphyletic taxon : A group composed of a collection of organisms, including the most recent common ancestor of all those organisms. Unlike a monophyletic group, a paraphyletic taxon does not include all the descendants of the most recent common ancestor.
Examples : Traditionally defined Dinosauria, fish, gymnosperms, invertebrates, protists, etc.

2.polyphyletic -- Term applied to a group of organisms which does not include the most recent common ancestor of those organisms; the ancestor does not possess the character shared by members of the group. More?

-Polyphyletic taxon : A group composed of a collection of organisms in which the most recent common ancestor of all the included organisms is not included, usually because the common ancestor lacks the characteristics of the group.
Polyphyletic taxa are considered "unnatural", and usually are reclassified once they are discovered to be polyphyletic.
Examples : marine mammals, bipedal mammals, flying vertebrates, trees, algae, etc.


3.monophyletic -- Term applied to a group of organisms which includes the most recent common ancestor of all of its members and all of the descendants of that most recent common ancestor. A monophyletic group is called a clade

-Monophyletic taxon : A group composed of a collection of organisms, including the most recent common ancestor of all those organisms and all the descendants of that most recent common ancestor. A monophyletic taxon is also called a clade.
Examples : Mammalia, Aves (birds), angiosperms, insects, etc.