Ardei

Suborder of birds

Ardei is a suborder of order Pelecaniformes that include the families Ardeidae and Threskiornithidae. Traditionally the ardeids and threskiornithids were classified in the order Ciconiiformes along with Ciconiidae (storks), Phoenicopteridae (flamingos), Scopidae (hamerkop), Balaenicipitidae (shoebill), and even Cathartidae. However, there were some osteological studies that have questioned the monophyly of Ciconiiformes, suggesting that the ardeids and threskiornithids originated from early gruiforms, with the latter being a transitionary taxon to order Charadriiformes. The non-monophyletic nature of Ciconiiformes is supported by recent genomic studies that have found support for threskiornithids, ardeids, scopids and balaenicipitids being closely related to Pelecanidae (pelicans).

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