Beck, Robin M DBininda-Emonds, Olaf RPCardillo, MarcelLiu, Fu-GuoPurvis, Andy2016-01-212016-01-211471-2148http://hdl.handle.net/1885/95570BACKGROUND The higher-level phylogeny of placental mammals has long been a phylogenetic Gordian knot, with disagreement about both the precise contents of, and relationships between, the extant orders. A recent MRP supertree that favoured 'outdated' hypotheses (notably, monophyly of both Artiodactyla and Lipotyphla) has been heavily criticised for including low-quality and redundant data. We apply a stringent data selection protocol designed to minimise these problems to a much-expanded data set of morphological, molecular and combined source trees, to produce a supertree that includes every family of extant placental mammals. RESULTS The supertree is well-resolved and supports both polyphyly of Lipotyphla and paraphyly of Artiodactyla with respect to Cetacea. The existence of four 'superorders'--Afrotheria, Xenarthra, Laurasiatheria and Euarchontoglires--is also supported. The topology is highly congruent with recent (molecular) phylogenetic analyses of placental mammals, but is considerably more comprehensive, being the first phylogeny to include all 113 extant families without making a priori assumptions of suprafamilial monophyly. Subsidiary analyses reveal that the data selection protocol played a key role in the major changes relative to a previously published higher-level supertree of placentals. CONCLUSION The supertree should provide a useful framework for hypothesis testing in phylogenetic comparative biology, and supports the idea that biogeography has played a crucial role in the evolution of placental mammals. Our results demonstrate the importance of minimising poor and redundant data when constructing supertrees.Financial support was provided by the BMBF (Germany) through the "Bioinformatics for the Functional Analysis of Mammalian Genomes" project (ORPBE), and by NERC (UK) through research grant NER/A/S/2001/00581 (RMDB, AP, MC). Further financial support during the write-up of this work was provided by the Leverhulme Trust through Study Abroad Studentship SAS/30110 (RMDB).© Beck et al. 2006 This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://​creativecommons.​org/​licenses/​by/​2.​0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.animalsbiological evolutionhumansmammalsmodels, statisticalphylogenyplacentaspecies specificityevolution, molecular2006-11-1310.1186/1471-2148-6-932016-02-24