Stiphrornis

The genus Stiphrornis was introduced in 1855 by the German ornithologist Gustav Hartlaub with Stiphrornis erythrothorax Hartlaub (the orange-breasted forest robin) as the type species.^[1][2] The genus name combines the Ancient Greek στιφρος/stiphros meaning "sturdy" or "stout" with ορνις/ornis meaning "bird".^[3]

All taxa within the genus Stiphrornis were formerly considered to comprise a single species, the forest robin (S. erythrothorax), but in 1999, it was argued, based on the phylogenetic species concept, that all then-recognized taxa should be considered separate monotypic species.^[4] The split was not followed in 2005 by the Handbook of the Birds of the World, where it was described as "perhaps premature".^[5] An additional taxon, Stiphrornis pyrrholaemus (the olive-backed forest robin) was described as a new species in 2008,^[6] but this taxon was treated as a subspecies of the forest robin in 2014 in the fourth edition of the Howard and Moore Complete Checklist of the Birds of the World.^[7]

In 2017 Garry Voelker and collaborators described three additional taxa in the forest robin species complex and in the same article reported the results of a molecular phylogenetic study of the complex. The authors chose to treat all eight taxa as separate species,^[8] but other ornithologists have not followed this lead and have instead divided the taxa into three species.^[9][10][11]

The genus contains three species:^[9]

• Orange-breasted forest robin, Stiphrornis erythrothorax
• Yellow-breasted forest robin, Stiphrornis xanthogaster
• Olive-backed forest robin, Stiphrornis pyrrholaemus

The cladogram below showing the relationships between the taxa is based on a molecular phylogenetic study by Garry Voelker and collaborators that was published in 2017.^[8] The species are those recognised by Frank Gill, Pamela C. Rasmussen and David Donsker in the list of world birds maintained on behalf of the International Ornithological Committee (IOC).^[9]