Dunes in the world’s big rivers are characterized by low-angle lee-side slopes and a complex shape - Cisneros, Julia; Best, Jim; van Dijk, Thaiënne; Almeida, Renato Paes de; Amsler, Mario; Boldt, Justin; Freitas, Bernardo Tavares; Galeazzi, Cristiano Padalino; Huizinga, Richard; Ianniruberto, Marco; Ma, Hongbo; Nittrouer, Jeffrey A.; et al. (Nature Geoscience, 2020)