The paedomorphosis syndrome (PDM) is a phenomenon in which individuals retain juvenile traits or features into adulthood, resulting in a resemblance of adults with their young forms. Overall, our knowledge about the effects and causes of the PDM in animals is fragmentary. In beetles, the PDM has evolved multiple times in several unrelated lineages, such as fireflies and click-beetles. Our knowledge about the effects and causes of PDM in beetles is as fragmentary as in animals in general. It is currently unknown whether the paedomorphic modifications in different beetle lineages have the same evolutionary origins or if they have evolved independently. These gaps negatively impact our understanding of how PDM shapes the evolution of organisms. This study aimed to (1) Identify and document morphological changes in paedomorphic lineages across the Coleoptera, 2) Test hypotheses of homology for morphological characters heavily affected by PDM in a phylogenetic framework using beetles of the tribe Calopterini (Lycidae) as example, and 3) Identify evolutionary causes for the repeated and independent development of PDM in beetles as a model to understand convergent phenotypes in animal evolution.