The stalked barnacle Dosima fascicularis is reported from Uruguayan waters for the first time based on stranded specimens. It is suggested that the Subtropical Front is the main area of occurrence of D. fascicularis in the South Atlantic and its occurrence on the Uruguayan coast was found to be sporadic and mainly related to singular atmospheric and oceanographic factors that cast ‘blue plankton’ ashore (e.g. easterly and south-easterly winds, and prevalence of tropical waters).

The taxonomy and distribution patterns of the common dolphins (genus Delphinus) are problematic among cetaceans and particularly complicated in the south-western Atlantic Ocean. On the basis of national collections, we found ten adult skulls of the genus Delphinus of Uruguayan origin. The two currently recognized species for the genus were identified based on craniometric measurements: the pelagic short beaked form (Delphinus delphis, N = 3) and the coastal long beaked form (Delphinus capensis, N = 4), although previous studies only recognized D. capensis for Uruguay. Three specimens could not be identified (Delphinus sp.) because of broken skull (2) and intermediate measures (1). This result is consistent with a recent review on the biogeography of the genus in the south-western Atlantic Ocean.