Mirandornithes () is a

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

that consists of

flamingos Flamingos or flamingoes () are a type of wading bird in the family Phoenicopteridae, which is the only extant family in the order Phoenicopteriformes. There are four flamingo species distributed throughout the Americas (including the Caribbe ...

and

grebes Grebes () are aquatic diving birds in the order Podicipediformes (). Grebes are widely distributed freshwater birds, with some species also found in marine habitats during migration and winter. Most grebes fly, although some flightless species ...

. Many scholars use the term Phoenicopterimorphae for the superorder containing flamingoes and grebes. Determining the relationships of both groups has been problematic. Flamingos had been placed with numerous branches within

Neognathae Neognathae (; ) is an infraclass of birds, called neognaths, within the class Aves of the clade Archosauria. Neognathae includes the majority of living birds; the exceptions being the tinamous and the flightless ratites, which belong instead to t ...

, such as

ducks Duck is the common name for numerous species of waterfowl in the family (biology), family Anatidae. Ducks are generally smaller and shorter-necked than swans and goose, geese, which are members of the same family. Divided among several subfam ...

and

storks Storks are large, long-legged, long-necked wading birds with long, stout Beak, bills. They belong to the family (biology), family Ciconiidae, and make up the order Ciconiiformes . Ciconiiformes previously included a number of other families, suc ...

. The grebes had been placed with the

loon Loons (North American English) or divers (British English, British / Irish English) are a group of aquatic birds found in much of North America and northern Eurasia. All living species of loons are members of the genus ''Gavia'', family (biolog ...

s. However more recent genomic studies have confirmed these two branches as sister groups. Both primitive

phoenicopteriformes Phoenicopteriformes is a group of water birds which comprises flamingos and their extinct relatives. Flamingos (Phoenicopteriformes) and the closely related grebes ( Podicipedidae) are contained in the parent clade Mirandornithes. Fossil ...

and their closest relatives, the

grebe Grebes () are aquatic diving birds in the order (biology), order Podicipediformes (). Grebes are widely distributed freshwater birds, with some species also found in sea, marine habitats during Bird migration, migration and winter. Most grebes f ...

s, were highly aquatic.Mayr, G. (2014) The Eocene ''Juncitarsus'' – its phylogenetic position and significance for the evolution and higher-level affinities of flamingos and grebes. ''Comptes Rendus Palevol''. 13(1):9-18. https://doi.org/10.1016/j.crpv.2013.07.005 This indicates that the entire mirandornithe group evolved from aquatic, probably swimming ancestors.

Etymology

The term was coined by Sangster in 2005, in order to properly describe the new clade discovered with molecular analyses. It is inspired by the Latin , meaning "wonderful", and the Greek ὄρνις (''órnis''), meaning bird.

Synapomorphies

According to Mayr (2004) and Sangster (2005) there are at least twelve distinct morphological

synapomorphies In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to ...

that are unique to this clade: # "At least the fourth to seventh cervical vertebrae strongly elongate, with processus spinosus forming a marked ridge. # Humerus with a marked oval depression at insertion site of musculus scapulohumeralis cranialis. # At least 23 presacral vertebrae. # At least four thoracic vertebrae fused to a notarium. # Distal end of ulna with marked oval depression radialis. # Phalanx proximalis digiti majoris very elongate and narrow craniocaudally. # Distal rim of condylus medialis of tibiotarsus distinctly notched. # Pars acetabularis of musculus iliotibialis lateralis absent. # Pars caudalis of musculus caudofemoralis absent. # Wing with 12 primaries # Left arteria carotis reduced or absent. # Eggs covered with a chalky layer of amorphous

calcium phosphate The term calcium phosphate refers to a family of materials and minerals containing calcium ions (Ca2+) together with inorganic phosphate anions. Some so-called calcium phosphates contain oxide and hydroxide as well. Calcium phosphates are white ...

References

{{Taxonbar, from=Q5891686 Neognathae