 Given that they are almost as distant from the rollers, kingfishers and allies as are the trogons, the arrangement chosen is more a matter of personal taste than any well-established taxonomic practice.All that can be said with reasonable certainty is that placing the hornbills outside the Coraciiformes and the trogons inside would be incorrect.Recent genetic data suggests that ground hornbills and "Bycanistes" form a clade outside the rest of the hornbill lineage.