synapomorphy

noun

syn·​ap·​o·​mor·​phy (ˌ)si-ˈna-pə-ˌmȯr-fē 

plural synapomorphies

: a character or trait that is shared by two or more taxonomic groups and is derived through evolution from a common ancestral form

Word History

Etymology

International Scientific Vocabulary syn- + apomorphy derived evolutionary trait or feature (from apo- + -morphy)

First Known Use

1965, in the meaning defined above