Taxonomy
The Shoebill was only classified in the 19th century when some skins were brought to Europe. It was not until years later that live specimens reached the scientific community. However, the bird was known to both ancient Egyptians and Arabs. Traditionally allied with the storks (Ciconiiformes), it was retained there in the Sibley-Ahlquist taxonomy which lumped a massive number of unrelated taxa into their "Ciconiiformes". More recently, the shoebill has been considered to be closer to the pelicans (based on anatomical comparisons) or the herons (based on biochemical evidence; Hagey et al., 2002). A recent DNA study suggests they are part of the Pelecaniformes.
The dispute has turned out to be mainly one of where to draw the boundary between Ciconiiformes and Pelecaniformes, or whether to draw it at all. Since cormorants and relatives are probably not actually Pelecaniformes, a solution adopted by some modern authors is to merge the "core" Pelecaniformes with the Ciconiiformes. The Shoebill and the Hammerkop (Scopus umbretta) are the "missing links" that connect pelicans and storks, and including the pelican lineage in the Ciconiiformes expresses this more adequately than other treatments do.
So far, two fossil relatives of the shoebill have been described: Goliathia from the early Oligocene of Egypt and Paludavis from the Early Miocene of the same country. It has been suggested that the enigmatic African fossil bird Eremopezus was a relative too, but the evidence for that is unconfirmed. All that is known of Eremopezus is that it was a very large, probably flightless bird with a flexible foot, allowing it to handle either vegetation or prey.
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