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Joseph W. Brown and John Harshman
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taxon links [up-->]Fregatidae [up-->]Anhingidae [up-->]Phalacrocoracidae [up-->]Scopus umbretta [up-->]Ardeidae [up-->]Threskiornithidae [up-->]Pelecanidae [up-->]Sulidae [up-->]Balaeniceps rex [down<--]'Water Birds' Interpreting the tree
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This tree diagram shows the relationships between several groups of organisms.

The root of the current tree connects the organisms featured in this tree to their containing group and the rest of the Tree of Life. The basal branching point in the tree represents the ancestor of the other groups in the tree. This ancestor diversified over time into several descendent subgroups, which are represented as internal nodes and terminal taxa to the right.

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You can click on the root to travel down the Tree of Life all the way to the root of all Life, and you can click on the names of descendent subgroups to travel up the Tree of Life all the way to individual species.

For more information on ToL tree formatting, please see Interpreting the Tree or Classification. To learn more about phylogenetic trees, please visit our Phylogenetic Biology pages.

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Phylogenetic hypothesis based on Hackett et al. (2008).

Containing group: 'Water Birds'

Discussion of Phylogenetic Relationships

Traditionally, Pelecaniformes also includes the family Phaethontidae (tropicbirds), which is only distantly related to the other families. Several families included here are traditionally considered to belong to Ciconiiformes: Threskiornithidae, Ardeidae, Balaeniceps, and Scopus (Hackett et al. 2008).


Cracraft, J. 1985. Monophyly and the phylogenetic relationships of the Pelecaniformes: a numerical cladistic analysis. Auk 102: 834-853.

Cracraft, J., F. Keith Barker, M. J. Braun, J. Harshman, G. Dyke, J. Feinstein, S. Stanley, A. Cibois, P. Schikler, P. Beresford, J. García-Moreno, M. D. Sorenson, T. Yuri, and D. P. Mindell. 2004. Phylogenetic Relationships Among Modern Birds (Neornithes): Toward an Avian Tree of Life. Pp 468-489 in Cracraft, J. and M. J. Donoghue (eds.), Assembling the Tree of Life. Oxford University Press, New York.

Fain, M. G., and P. Houde. 2004. Parallel radiations in the primary clades of birds. Evolution 58:2558-2573.

Hackett, S. J., Kimball, R. T., Reddy, S., Bowie, R. C. K., Braun, E. L., Braun, M. J., Chojnowski, J. L., Cox, W. A., Han, K.-L., Harshman, J., Huddleston, C. J., Marks, B. D., Miglia, K. J., Moore, W. A., Sheldon, F. H., Steadman, D. W., Witt, C. C., and Yuri, T. 2008. A phylogenomic study of birds reveals their evolutionary history. Science 320(5884):1763-1768.

Hedges, S. B., and Sibley, C. G. 1994. Molecules vs. morphology in avian evolution: The case of the "pelecaniform" birds. Proc. Natl. Acad. Sci. USA 91: 9861-9865.

Johnsgaard, P. A. 1993. Cormorants, Darters, and Pelicans of the World. Smithsonian Institution Press, Washington DC.

Kennedy, M., Holland, B.R., Gray, R.D., and Spencer, H.G. 2005. Untangling long branches: Identifying conflicting phylogenetic signals a priori using spectral analysis, neighbor-net, and consensus networks. Systematic Biology 54:620-633.

Kennedy, M. and H. G. Spencer. 2004. Phylogenies of the frigatebirds (Fregatidae) and tropicbirds (Phaethontidae), two divergent groups of the traditional order Pelecaniformes, inferred from mitochondrial DNA sequences. Molecular Phylogenetics and Evolution 31:31-38.

Kennedy, M., H. G. Spencer, and R. D. Gray. 2000. Hop, step and gape: do the social displays of the Pelecaniformes reflect phylogeny? Animal Behaviour 51: 273-291.

Livezey, B. C., and R. L. Zusi. 2007. Higher-order phylogeny of modern birds (Theropoda, Aves: Neornithes) based on comparative anatomy. II. Analysis and discussion. Zool. J. Linn. Soc. 149:1-95.

Mayr, G. 2003. On the phylogenetic relationships of trogons (Aves, Trogonidae). J. Avian Biol. 34:81-88.

Nelson, J. B. 2006. Pelicans, Cormorants, and Their Relatives: The Pelecaniformes. Bird Families of the World. Oxford University Press, Oxford, New York.

Sheldon, F. H. and B. Slikas. 1997. Advances in Ciconiiform Systematics. Colonial Waterbirds 20(1):106-114.

Sibley, C. G. and J. E. Ahlquist. 1990. Phylogeny and classification of birds: a study in molecular evolution. Yale University Press, New Haven.

Siegel-Causey, D. 1997. Phylogeny of the Pelecaniformes: molecular systematics of a privative group. Pp 159-171 in Mindell, D. P. (ed.), Avian Molecular Evolution and Systematics. Academic Press, San Diego.

van Tuinen, M., D. B. Butvill, J. A. W. Kirsch, and S. B. Hedges. 2001. Convergence and divergence in the evolution of aquatic birds. Proc. R. Soc. Lond. B 268:1345-1350.

Information on the Internet

Title Illustrations
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Scientific Name Nycticorax nycticorax
Location Caye Caulker, Belize
Creator John J. Mosesso
Specimen Condition Live Specimen
Source Collection NBII Digital Image Library
Scientific Name Pelecanus thagus
Location Chile
Specimen Condition Live Specimen
Source Peruvian Pelican Pelecanus thagus
Copyright © 2005 Arthur Grosset
Scientific Name Phalacrocorax carbo
Location Japan
Specimen Condition Live Specimen
Source Clothes Drying
Source Collection Flickr
Image Use creative commons This media file is licensed under the Creative Commons Attribution-ShareAlike License - Version 2.0.
Copyright © 2004 Charles Lam
About This Page

Joseph W. Brown
University of Michigan Museum of Zoology, Ann Arbor, Michigan, USA

Correspondence regarding this page should be directed to Joseph W. Brown at and John Harshman at

Page: Tree of Life Pelecaniformes. Authored by Joseph W. Brown and John Harshman. The TEXT of this page is licensed under the Creative Commons Attribution-NonCommercial License - Version 3.0. Note that images and other media featured on this page are each governed by their own license, and they may or may not be available for reuse. Click on an image or a media link to access the media data window, which provides the relevant licensing information. For the general terms and conditions of ToL material reuse and redistribution, please see the Tree of Life Copyright Policies.

Citing this page:

Brown, Joseph W. and John Harshman. 2008. Pelecaniformes. Version 27 June 2008 (under construction). http://tolweb.org/Pelecaniformes/57152/2008.06.27 in The Tree of Life Web Project, http://tolweb.org/

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This page is a Tree of Life Branch Page.

Each ToL branch page provides a synopsis of the characteristics of a group of organisms representing a branch of the Tree of Life. The major distinction between a branch and a leaf of the Tree of Life is that each branch can be further subdivided into descendent branches, that is, subgroups representing distinct genetic lineages.

For a more detailed explanation of the different ToL page types, have a look at the Structure of the Tree of Life page.

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