From Fensome et al., 2019:

Islandinium, Head et al. 2001, p.629.
Taxonomic junior synonym: Cantiacidinium (name not validly published), by implication in Head et al. (2001, p.629), who considered the only recorded species name, Cantiacidinium conicum (name not validly published), to be a taxonomic junior synonym of Islandinium minutum.
Type: Harland et al., 1980, fig.2O, as Multispinula? minuta.

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Original description: [Head et al., 2001]:

Diagnosis:
Cysts brown in colour, having spheroidal central body whose wall is smooth to finely ornamented.Processes numerous, non-tabular, terminating distally inacuminate or expanded, including branched, tips. Principal and occasionally accessory archeopyle sutures are only clear expression of tabulation.
Archeopyle saphopylic Type A3,formed by loss of three apical plates, 2′,3′and 4′. Operculum free; opercular pieces lost separately.