Pgp. Ericson, SYSTEMATIC RELATIONSHIPS OF THE PALEOGENE FAMILY PRESBYORNITHIDAE (AVES, ANSERIFORMES), Zoological journal of the Linnean Society, 121(4), 1997, pp. 429-483
The early Tertiary (Paleocene and Eocene) family Presbyornithidae is o
ne of the most completely known group of fossil birds. Essentially all
parts of the skeleton are represented in the fossil record, allowing
a thorough analysis of the phylogenetic position of the family. Forty-
two families of nonpasserine birds representing the orders Ciconiiform
es, Anseriformes, Galliformes, Gruiformes and Charadriiformes, were in
cluded in a cladistic analysis of 71 skeletal characters. The previous
ly suggested anseriform affinity of the Presbyornithidae was confirmed
. Furthermore, the family proved to be closer to the Anatidae than to
the Anhimidae or Anseranatidae. The many postcranial similarities with
certain charadriiform birds as the Burhinidae, obviously are plesiomo
rphies. By this observation, a better undestanding of character evolut
ion in nonpasserine skeletal morphology is gained. The often suggested
close relationship of anseriform and galliform birds is not confirmed
by osteology. Instead, the Anseriformes and the Phoenicopteridae form
a monophyletic clade that is the sister to the remaining ciconiiform
birds. This result renders the Ciconiiformes sensu Wetmore (1960) poly
phyletic. (C) 1997 The Linnean Society of London.