Unveiling the Understudied: a Look at Phylogenetic Research on Mollusks in Brazil

Phylogenies are essential for organizing knowledge on biological diversity, structuring classifications, and providing insights into evolutionary events. Worldwide phylogenetic studies on mollusks emerged in the late 1980s, while in Brazil, phylogenetic analyses of mollusks started around 2000. For unknown reasons, phylogenies of lower hierarchical taxa, such as subfamilies, tribes, and genera, are not common in Malacology. Here, we analyzed articles published by malacologists and evaluated the proportion of alpha taxonomic reviews compared to phylogenetic systematic studies conducted at Brazilian institutions and worldwide. Our searches were performed using the Web of Science and Lattes Platform databases for Brazilian studies. We found 537 systematic/taxonomic papers, of which 11% included an explicit phylogenetic analysis. Additionally, 31 of these studies described a new genus or higher taxon, but only seven included phylogenetic inferences to support taxonomic decisions. The remaining 24 studies relied on alpha taxonomic classification, focusing primarily on conchological features of group-related units. We observed that publications worldwide describing higher taxa based on phylogenetic systematics began in the 1970s, with their proportion increasing over the years. The few phylogenetic analyses published after Willi Hennig’s cladistics suggest that malacologists at Brazilian institutions have not established a tradition of Phylogenetic Systematics for studies on molluscan diversity.