© 2018 The Linnean Society of London, Zoological Journal of the Linnean Society, 2018, XX, 1–14 1 Zoological Journal of the Linnean Society, 2018, XX, 1–14. With 5 figures. Solving a thorny situation: DNA and morphology illuminate the evolution of the leaf beetle tribe Dorynotini (Coleoptera: Chrysomelidae: Cassidinae) MARIANNA V. P. SIMÕES 1, * , , STEPHEN M. BACA 2 , EMMANUEL F. A. TOUSSAINT 3 , DONALD M. WINDSOR 4 and ANDREW E. Z. SHORT 2 1 Department of Marine Zoology-Crustaceans, Senckenberg Research Institute and Natural History Museum, Senckenberganlage 25, 60325 Frankfurt am Main, Germany 2 Department of Ecology and Evolutionary Biology; and Division of Entomology, Biodiversity Institute, University of Kansas, Lawrence, KS 66045, USA 3 Florida Museum of Natural History, University of Florida, Powell Hall, 3215 Hull Road, Gainesville, FL 32611–2710, USA 4 Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Republica de Panamá Received 7 March 2018; revised 28 June 2018; accepted for publication 10 September 2018 The Neotropical tribe Dorynotini is characterized by a conspicuous tubercle or spine adorning the elytra, which, along with a few other characters, has been used to differentiate its recognized five genera and two subgenera. However, relationships among these taxa and the evolutionary origin of the pronounced tubercle remain speculative. Here we present the first total-evidence phylogenetic reconstruction of Dorynotini to investigate the homology and evolution of the elytral tubercle. Our analyses are based on 89 discrete morphological characters and DNA sequence data from three gene regions. Phylogenetic relationships were inferred using Bayesian inference, maximum likeli- hood and maximum parsimony. Our analyses support the respective monophyly of Dorynotini and its genera and subgenera, except the paraphyletic Dorynota s.s. Species endemic to the Greater Antilles form a clade with three distinct morphotypes. Omoteina aculeata (Boheman, 1854) nov. comb. is transferred from the genus Dorynota, and Paratrikona Spaeth, 1923 nov. syn. is found to be congeneric with Omoteina Chevrolat, 1836. The spiniform projection is found to be plesiomorphic within Dorynotini and convergently reduced/lost in different lineages of the tribe. Some morphological characters defining dorynotine taxa are homoplastic, requiring re-evaluation guided by molecular analyses for more accurate classification and an improved understanding of taxon evolution. ADDITIONAL KEYWORDS: ancestral character reconstructionn – Caribbean – Insecta – insect phylogeny – molecular systematics – Neotropical – phylogenetic systematics – phylogenetics, Bayesian analysis – phylogenetics, maximum likelihood – taxa, new classification – taxonomy – total-evidence phylogenetic reconstruction. INTRODUCTION Cassidinae s.l., commonly known as tortoise beetles, is the second largest subfamily of leaf beetles, with ~6300 described species worldwide (Borowiec & Świętojańska, 2018). The tribe Dorynotini Monrós & Viana, 1949 is an exclusively Neotropical clade of cassidines (Chaboo, 2007) distributed from central Mexico to northern Argentina, including the Greater Antilles (Borowiec & Świętojańska, 2018). The tribe currently contains 56 spe- cies distributed in five genera: Dorynota Chevrolat, 1836, Heteronychocassis Spaeth, 1915 (one species), Omoteina Chevrolat, 1836 (one species), Paranota Monrós & Viana, 1949 (five species) and Paratrikona Spaeth, 1923 (seven species). The most diverse genus, Dorynota, is further split into two subgenera: Dorynota s.s. (18 species) and Akantaka Maulik, 1916 (24 species) (Bouchard et al., 2011; Simões, 2014; Simões & Sekerka, 2014; Simões & Sekerka, 2015; Borowiec & Świętojańska, 2018). Chevrolat (in Dejean, 1836) first proposed the genus Dorynota for Neotropical cassidines with a *Corresponding author. E-mail: mariannavpsimoes@gmail.com Downloaded from https://academic.oup.com/zoolinnean/advance-article-abstract/doi/10.1093/zoolinnean/zly079/5220517 by guest on 03 December 2018