Chrysochromulina pseudolanceolata is a marine haptophyte microalga in the genus Chrysochromulina, class Prymnesiophyceae, order Prymnesiales. The prefix pseudo — meaning false or resembling — combined with lanceolata indicates that this species closely resembles C. lanceolata in overall appearance or scale form but is distinguished by subtle ultrastructural differences that justify its treatment as a separate species. Such pseudo-named species are common in groups where morphological convergence is high, and they emphasize the need for careful electron microscopy to avoid misidentification. C. pseudolanceolata has been recorded from Norwegian and Swedish coastal marine waters and also from Brazilian waters, suggesting a broad Atlantic distribution shared with its namesake C. lanceolata. This Atlantic-spanning distribution may reflect genuine cosmopolitan dispersal of marine nanoplankton facilitated by ocean current systems, or alternatively may result from independent description of morphologically similar but genetically distinct lineages from different ocean regions. The species inhabits coastal photic zones and contributes to primary production as a photoautotrophic or mixotrophic nanoplankton organism. Its golden-brown pigmentation derives from the characteristic prymnesiophyte combination of chlorophylls a and c with fucoxanthin. C. pseudolanceolata has not been assessed under IUCN criteria and is classified as Not Evaluated. Molecular phylogenetic studies comparing Norwegian and Brazilian populations would help clarify whether geographically separated populations represent a single coherent species.