Nomenclatural note on a Thecadinium species (Dinophyceae, Gonyaulacales), which was described as new independently three times within two months

Three Thecadinium species, independently described as new in three separate publications, are actually regarded as conspecific. The combined plate formula is Po 3' 1a 6' 5-7/8c 5s 6'' 2''. The size range of the species is 38-65 l m in length and 23-42 lm in depth. It has one or two strongly lobed chloroplasts. The correct name of the species is Thecadinium yashimaense Yoshimatsu, Toriumi et Dodge 2004. Thecadinium mucosum Hoppenrath et Taylor 2004 and Thecadinium foveolatum Bolch 2004 are taxonomical synonyms. This note clarifies the plate tabulation and other features of the species.