Definition of synapomorphy in English:



  • 1A characteristic present in an ancestral species and shared exclusively (in more or less modified form) by its evolutionary descendants.

    ‘the study of skulls of this primitive reptile has led to the discovery of numerous synapomorphies with turtles’
    • ‘This observation hints at one putative morphological synapomorphy of a Petopentia / Periploca clade.’
    • ‘These four genera form a monophyletic group defined by one synapomorphy (loss of one anterior left marginal).’
    • ‘Those specimens include conclusive evidence of the strongest possible bird-theropod synapomorphy - completely modern feathers and the oldest, most birdlike dromaeosaurs.’
    • ‘But this is not very convincing, as it reveals only one valid synapomorphy.’
    • ‘The only known synapomorphy of this group is the presence of a sesamoid bone in the heel region.’
    1. 1.1mass noun Possession by two or more organisms of a characteristic inherited exclusively from their common ancestor.
      ‘synapomorphy delineates the relative status of particular features with respect to a specific evolutionary problem’
      • ‘It is through cladistic analysis that we are able to tell homoplasy from synapomorphy.’
      • ‘Based on cell lineages, the blastomere-by-blastomere derivation of most major larval organs, there is good reason to infer synapomorphy across the larvae of most lophotrochozoan phyla, if not the lophophorates.’
      • ‘This conflict can be resolved as either parallelism, reversal, or synapomorphy.’
      • ‘Thus, when a SINE sequence is found at an orthologous locus in two or more lineages, it can be regarded as evidence for synapomorphy.’
      • ‘The diagnosis of Glades through synapomorphy becomes the starting point for the investigation of functional, temporal, adaptive and biogeographic questions.’


1960s: from syn- ‘together’ + apo- ‘away from’ + Greek morphē ‘form’.