@article{TEXTUAL,
      recid = {10609},
      author = {Smith, Nathan D.},
      title = {Phylogenetic Analysis of Pelecaniformes (Aves) Based on  Osteological Data: Implications for Waterbird Phylogeny and  Fossil Calibration Studies},
      journal = {PLOS ONE},
      address = {2010-10-14},
      number = {TEXTUAL},
      abstract = {&lt;p&gt;Background: Debate regarding the monophyly and  relationships of the avian order Pelecaniformes represents  a classic example of discord between morphological and  molecular estimates of phylogeny. This lack of consensus  hampers interpretation of the group's fossil record, which  has major implications for understanding patterns of  character evolution (e.g., the evolution of wing-propelled  diving) and temporal diversification (e.g., the origins of  modern families). Relationships of the Pelecaniformes were  inferred through parsimony analyses of an osteological  dataset encompassing 59 taxa and 464 characters. The  relationships of the Plotopteridae, an extinct family of  wing-propelled divers, and several other fossil  pelecaniforms (&lt;em&gt;Limnofregata&lt;/em&gt;, &lt;em&gt;Prophaethon&lt;/em&gt;,  &lt;em&gt;Lithoptila&lt;/em&gt;, ?&lt;em&gt;Borvocarbo stoeffelensis&lt;/em&gt;)  were also assessed. The antiquity of these taxa and their  purported status as stem members of extant families makes  them valuable for studies of higher-level avian  diversification.&lt;/p&gt;&lt;p&gt;Methodology/Principal Findings:  Pelecaniform monophyly is not recovered, with Phaethontidae  recovered as distantly related to all other pelecaniforms,  which are supported as a monophyletic Steganopodes. Some  anatomical partitions of the dataset possess different  phylogenetic signals, and partitioned analyses reveal that  these discrepancies are localized outside of Steganopodes,  and primarily due to a few labile taxa. The Plotopteridae  are recovered as the sister taxon to Phalacrocoracoidea,  and the relationships of other fossil pelecaniforms  representing key calibration points are well supported,  including &lt;em&gt;Limnofregata&lt;/em&gt; (sister taxon to  Fregatidae), &lt;em&gt;Prophaethon&lt;/em&gt; and &lt;em&gt;Lithoptila&lt;/em&gt;  (successive sister taxa to Phaethontidae), and  ?&lt;em&gt;Borvocarbo stoeffelensis&lt;/em&gt; (sister taxon to  Phalacrocoracidae). These relationships are invariant when  ‘backbone’ constraints based on recent avian phylogenies  are imposed.&lt;/p&gt;&lt;p&gt;Conclusions/Significance: Relationships  of extant pelecaniforms inferred from morphology are more  congruent with molecular phylogenies than previously  assumed, though notable conflicts remain. The phylogenetic  position of the Plotopteridae implies that wing-propelled  diving evolved independently in plotopterids and penguins,  representing a remarkable case of convergent evolution.  Despite robust support for the placement of fossil taxa  representing key calibration points, the successive  outgroup relationships of several “stem fossil + crown  family” clades are variable and poorly supported across  recent studies of avian phylogeny. Thus, the impact these  fossils have on inferred patterns of temporal  diversification depends heavily on the resolution of deep  nodes in avian phylogeny.&lt;/p&gt;},
      url = {http://knowledge.uchicago.edu/record/10609},
}