RT Journal Article SR Electronic A1 Malavasi, Veronica A1 Pusztai, Martin A1 Jankowska, Katarzyna A1 Zakryś, Bożena A1 Škaloud, Pavel T1 Revisiting Chrysococcus (Chrysophyceae): new phylogenetic evidence and evolutionary implications JF Fottea YR 2025 DO 10.5507/fot.2025.001 UL https://fottea.czechphycology.cz/artkey/fot-000000-0596.php AB Loricate golden algae (Chrysophyceae) are photosynthetic microorganisms characterized by a lorica, a rigid or semi-rigid protective casing made of organic material, sometimes reinforced with silica or iron. The lorica's diverse shapes and intricate ornamentation serve as both adaptive strategies and taxonomic markers. Here, we identified, for the first time, the molecular phylogenetic position of a loricate genus Chrysococcus, based on genetic investigations of two freshwater populations in Poland. The genus was resolved to form a well-supported clade with Chrysosaccus within the order Chrysosaccales. Accordingly, this order represents one of the morphologically most diverse lineages of Chrysophyceae, including naked flagellates, coccoid organisms, amoebae and flagellates dwelling in loricae, and mucilage-secreting cells. The phylogenetic resolution of Chrysococcus provides key evidence for understanding the evolutionary transitions within Chrysophyceae, highlighting the complex relationships between loricate and non-loricate taxa.