The genus Spatuloricaria is diagnosed by a number of conspicuous characteristics that set it apart from other genera in the subfamily Loricariinae. The genus has a broad geographical distribution extending from Argentina to Panama. Despite the flood of new loricariid taxa described in the past decades, no new species of Spatuloricaria have been newly reported since 1945. In this paper, we report on a distinctive new species of the genus from the Rio Xingu and Rio Tapajós in the Amazon basin. The new species is distinguished from congeners by the lack of abdominal and preanal plates, in combination with the presence of five transversal dark-brown bands on the dorsum. It apparently is the only species in Spatuloricaria where males are smaller than females, a situation opposite of that in other species of the genus.