This is largely an Old Worldorder, with the representation in the New World limited to the dozen or so species of todies and motmots, and a mere handful of the more than a hundred species of kingfishers.
The name Coraciiformes means "raven-like". Specifically, it comes from the Latin language "corax", meaning "raven" and Latin "forma", meaning "form".<ref>Template:Cite book</ref>
Several extinct coraciiform families are only known from Paleogenefossils. They probably belong to the basal group and are sometimes difficult to assign because they were even closer still to the Piciformes (see alsoNeanis). In addition, there are some prehistoric genera which are likewise difficult to place into a family. At least the Eocoraciidae are very basal, but the Late Eocene (some 35 mya) Geranopteridae form a superfamilyCoracioidea with the extant rollers and ground-rollers already (Mayr & Mourer-Chauviré 2000). A few prehistoric taxa of the present-day families have been described; see the family articles for details.
Taxonomic sequence
Protornis, a fossil coraciiform from the Oligocene of SwitzerlandUnresolved
Genus Quasisyndactylus (fossil; Middle Eocene of Messel, Germany) - alcediniform, basal?
Genus Cryptornis (fossil; Late Eocene of France) – bucerotid? geranopterid?
Coraciiformes gen. et spp. indet. PQ 1216, QU 15640 (fossil; Late Eocene of Quercy, France: Mayr & Mourer-Chauviré 2000)
Genus Protornis (fossil: Oligocene of Switzerland) – basal to motmotids and meropids?
A recent study suggest that the following families may belong to a separate order called Bucerotiformes. The results still in dispute though.<ref>Template:Cite web</ref>
The Leptosomidae (cuckoo roller) probably do not belong here. The trogons are sometimes placed here as a family Trogonidae. The Late Eocene Palaeospizidae are sometimes also placed in the Coraciiformes, as are the Early to Middle Eocene Primobucconidae and the Middle Eocene to Early Oligocene Sylphornithidae. The Primobucconidae at least indeed seem to belong here.
Johansson, Ulf S. & Ericson, Per G. P. (2003): Molecular support for a sister group relationship between Pici and Galbulae (Piciformes sensu Wetmore 1960). J. Avian Biol.34(2): 185–197. Template:DoiPDF fulltext
Mayr, Gerald & Mourer-Chauviré, Cécile (2000): Rollers (Aves: Coraciiformes. s.s.) from the Middle Eocene of Messel (Germany) and the Upper Eocene of the Quercy (France). J. Vertebr. Paleontol.20(3): 533–546. DOI:10.1671/0272-4634(2000)020[0533:RACSSF]2.0.CO;2 PDF fulltext
Terres, John K. (1980) The Audubon Society Encyclopedia of North American Birds. Template:ISBN