Relationships and Evolution of Flamingos (Aves: Phoenicopteridae)

Olson, Storrs L., and Alan Feduccia. Relationships and Evolution of Flamingos (Aves: Phoenicopteridae). Smithsonian Contributions to Zoology, number 316, 73 pages, 40 figures, 2 tables, 1980.—Previous evidence supposedly showing a relationship between flamingos and either storks (Ciconiiformes) or ducks (Anseriformes) is re-examined in light of the recent hypothesis deriving flamingos from shorebirds of the order Charadriiformes. Anatomical characters used to indicate relationship between flamingos and storks are shown to consist entirely of primitive "non-anseriform" traits found in several other orders, including Charadriiformes. Most of the presumed anseriform characters of flamingos also occur in the Charadriiformes, as do all of the characters of flamingos that do not occur in either Ciconiiformes or Anseriformes. The distinctive life history and behavior of flamingos is demonstrated as being very similar to that of the Recurvirostridae (Charadriiformes), particularly the Australian Banded Stilt {Cladorhynchus leucocephalus), but is unlike that of storks or ducks. The appendicular myology of Cladorhynchus is described and is found to be quite similar to that of flamingos, whereas neither is close to storks. The thigh muscle M. iliotibialis medialis, heretofore considered unique to flamingos, was discovered in Cladorhynchus but not in other Recurvirostridae. Evidence from osteology, natal down, oology, and internal parasites strongly supports a charadriiform derivation of flamingos; pterylosis does not contradict such a relationship; and knowledge of the early evolution of flamingos and Anseriformes offers a logical explanation for their sharing similar mallophagan parasites. The earliest certain flamingo, from the early Middle Eocene of Wyoming, is described herein as a new monotypic genus and species that was intermediate in size and morphology between the Recurvirostridae and modern flamingos. Other aspects of paleontology of flamingos are discussed. Evolutionary steps in the development of filter feeding in birds are outlined. The structure of the feeding apparatus of flamingos is shown to be entirely different from that of the Anseriformes, but is strikingly convergent towards that of baleen whales. Morphological and behavioral precursors for filter feeding are shown to occur in the Charadriiformes but not in the Ciconiiformes. Flamingos (Phoenicopteridae) clearly belong in the order Charadriiformes, suborder Charadrii, immediately following the Recurvirostridae. OFFICIAL PUBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the Institution's annual report, Smithsonian Year. SERIES COVER DESIGN: The coral Montastrea cavemosa (Linnaeus). Library of Congress Cataloging in Publication Data Olson, Storrs L Relationships and evolution of flamingos (Aves, Phoenicopteridae) (Smithsonian contributions to zoology ; no. 316) Bibliography: p. 1. Flamingos—Evolution. 2. Flamingos—Classification. 3. Birds, Fossil. 4. Birds—Evolution. 5. Birds—Classification. I. Feduccia, J. Alan, joint author. II. Title. III. Series: Smithsonian Institution. Smithsonian contributions to zoology ; no 316 QL1.S54 no. 316 [QL696.C56] 591s [598'.34] 80-607058