The families Alcedinidae (kingfishers), Momotidae (motmots), Todidae (todies), Meropidae (bee-eaters), Coraciidae (rollers), Brachypteraciidae (ground-rollers), Leptosomidae (cuckoo-rollers), Phoeniculidae (woodhoopoes), Upupidae (hoopoes) and Bucerotidae (hornbills) are traditionally grouped in the Order Coraciiformes, but no external morphological character is commom to the whole order. A comparative study of the cranial osteology of the Coraciiformes seeks to find characters capable to diagnose the order or groups of taxa, serving yet as a source to provide characters for future phylogenetic analysis. As established by the external morphological data, the cranial osteology has ratified the broad morphological divergence among the Coraciiformes taxa. Only two characters are common to the Order as a whole, as the presence of the laterosphenoid fossa and the absence of the suprameatic process, but these characters are not exclusive of the order. Primary homologies were found, showing similarities among several families, such as: the craniofacial flexion zone is an indefinite region in adults of the Coraciidae, Leptosomidae, Phoeniculidae, Upupidae and Bucerotidae; the temporal fossa has intermediate development and deepy in the Momotidae, Meropidae, Coraciidae, Brachypteraciidae and Bucerotidae; the lacrimal bone is absent in the Momotidae, fused with the ectethmoid in adults of the Upupidae, Phoeniculidae and Bucerotidae, and present and free in the Alcedinidae, Todidae, Meropidae, Coraciidae, Brachypteraciidae and Leptosomidae; and the o retroarticular process of the mandible is developed in the Upupidae, Phoeniculidae and Bucerotidae.
Mandible; morphology; skull
