Phylogeny of rodents in the family Echimyidae and their relatives. The four arboreal clades are: (a) tree rats (pictured: Makalata sp.), (b) spiny tree-rats (pictured: Lonchothrix emiliae and Mesomys stimulax), (c) bamboo rats (pictured: Dactylomys dactylinus), (d) and brush-tailed rats (pictured: Isothrix bistriata). Evolutionary relationships were inferred from the Bayesian analysis of the combined 5-gene data set (cyt-b + 12S rRNA + GHR + vWF + RAG1). Numbers at nodes refer to values listed in Table 2 for Bayesian posterior probability (PP) and maximum likelihood bootstraps (ML). Thick branches indicate statistically supported relationships >0.95 PP and >75 ML. See Table 1 and Additional file 1 for details of gene sampling and specimen localities. Rodent illustrations are by Fiona A. Reid  and are reprinted with permission.