The beetle tree of life reveals thatColeoptera survived end‐Permian mass extinction to diversify during theCretaceous terrestrial revolution
Authors: MCKENNA DUANE D. , WILD ALEXANDER L. , KANDA KOJUN , BELLAMY CHARLES L. , BEUTEL ROLF G. , CATERINO MICHAEL S. , FARNUM CHARLES W. , HAWKS DAVID C. , IVIE MICHAEL A. , JAMESON MARY LIZ , LESCHEN RICHARD A. B. , MARVALDI ADRIANA E. , MCHUGH JOSEPH V. , NEWTON ALFRED F. , ROBERTSON JAMES A. , THAYER MARGARET K. , WHITING MICHAEL F. , LAWRENCE JOHN F. , ŚLIPIŃSKI ADAM , MADDISON DAVID R. , FARRELL BRIAN D. 
Published: July 2015

Here we present a phylogeny of beetles (Insecta:Coleoptera) based onDNAsequence data from eight nuclear genes, including six single‐copy nuclear protein‐coding genes, for 367 species representing 172 of 183 extant families. Our results refine existing knowledge of relationships among major groups of beetles. Strepsiptera was confirmed as sister toColeoptera and each of the suborders ofColeoptera was recovered as monophyletic. Interrelationships among the suborders, namelyPolyphaga (Adephaga (Archostemata,Myxophaga)), in our study differ from previous studies. Adephaga comprised two clades corresponding toHydradephaga andGeadephaga. The series and superfamilies ofPolyphaga were mostly monophyletic. The traditionalCucujoidea were recovered in three distantly related clades. Lymexyloidea was recovered withinTenebrionoidea. Several of the series and superfamilies ofPolyphaga received moderate to maximal clade support in most analyses, for exampleBuprestoidea,Chrysomeloidea,Coccinelloidea,Cucujiformia,Curculionoidea,Dascilloidea,Elateroidea,Histeroidea andHydrophiloidea. However, many of the relationships withinPolyphaga lacked compatible resolution under maximum‐likelihood andBayesian inference, and/or lacked consistently strong nodal support. Overall, we recovered slightly younger estimated divergence times than previous studies for most groups of beetles. The ordinal split betweenColeoptera andStrepsiptera was estimated to have occurred in theEarlyPermian. CrownColeoptera appeared in the LatePermian, and only one or two lineages survived the end‐Permian mass extinction, with stem group representatives of all four suborders appearing by the end of theTriassic. The basal split inPolyphaga was estimated to have occurred in theTriassic, with the stem groups of most series and superfamilies originating during theTriassic orJurassic. Most extant families of beetles were estimated to haveCretaceous origins. Overall,Coleoptera experienced an increase in diversification rate compared to the rest ofNeuropteroidea. Furthermore, 10 family‐level clades, all in suborderPolyphaga, were identified as having experienced significant increases in diversification rate. These include most beetle species with phytophagous habits, but also several groups not typically or primarily associated with plants. Most of these groups originated in theCretaceous, which is also when a majority of the most species‐rich beetle families first appeared. An additional 12 clades showed evidence for significant decreases in diversification rate. These clades are species‐poor in theModern fauna, but collectively exhibit diverse trophic habits. The apparent success of beetles, as measured by species numbers, may result from their associations with widespread and diverse substrates – especially plants, but also including fungi, wood and leaf litter – but what facilitated these associations in the first place or has allowed these associations to flourish likely varies within and between lineages. Our results provide a uniquely well‐resolved temporal and phylogenetic framework for studying patterns of innovation and diversification inColeoptera, and a foundation for further sampling and resolution of the beetle tree of life.