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In the course of investigating the relationships of flamingos (Phoenicopteridae), it became increasingly apparent to me that the order Ciconiiformes is probably an entirely artificial assemblage consisting of various long-legged, long-necked, altricial waterbirds having little else in common. The charadriiform affinities of flamingos are being documented in some detail elsewhere (Olson and Feduccia, MS) and I shall attempt here only a summary of the evidence assembled so far in that regard. I would like to use this opportunity to put on record some preliminary ideas concerning the possible relationships of the remaining five families of Ciconiiformes (storks, Ciconiidae; shoebill stork, Balaenicipitidae; hammerhead, Scopidae; ibises and spoonbills, Threskiornithidae; herons, Ardeidae).
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Storrs L. Olson (1979) studied this question.
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