Radiolarians have long been recognized as a ubiquitous group of protistan microzooplankton in the world’s oceans. However, little is known about their biogeographic distributions and ecological interactions. To date, most radiolarian research has focused on their biostratigraphic fossil record, and has rarely attempted to inventory diversity, map species distributions, or determine ecological roles. Recent molecular barcoding has pioneered a more comprehensive and efficient approach to plankton research. Initial results show radiolarians to be among the most diverse and abundant clades in the sunlit ocean, with great impact on the marine food web and carbon cycle. Therefore, it is critical that we gain a better understanding of how radiolarians interact with biotic and abiotic variables, in order to accurately interpret their fossil record and predict responses to climate change. RADCODE will use molecular barcodes to explore the taxonomic diversity of poorly-known assemblages and investigate their environmental distributions and ecological interaction networks. Barcodes of deep-dwelling taxa will be identified from field samples and paired with micropaleontological classifications to develop integrated species concepts. Occurrences will be mapped globally using existing environmental DNA datasets to build the first atlas of morpho-molecular radiolarian taxa. By linking metadata from sample habitats, RADCODE will characterize the main factors impacting modern radiolarian biogeography, informing fossil record interpretation and modeling of future ecosystems. RADCODE is a highly interdisciplinary project that incorporates micropaleontological, biological, ecological, and environmental information, leading to a more unified approach to plankton research. This work will constitute a major step in my career, as I learn new research methods outside my discipline of training, and build a unique skillset that will set me apart among radiolarian workers.