From Fensome et al., 2019:
Diconodinium minutum (Deflandre and Cookson, 1955, p.257, text-fig.4) Deflandre and Deflandre-Rigaud, 1966, fiche 2967.
Holotype: Deflandre and Cookson, 1955, text-fig.4. Originally Palaeohystrichophora, subsequently (and now)
Diconodinium. Taxonomic junior synonym: Deflandrea (as Alterbia; now Isabelidinium) balmei, according to
Morgan (1977, p.130) — however, Lentin and Williams (1981, p.156) retained Deflandrea (as Isabelidinium)
balmei. Age: Santonian.

---------------------------------------------------------------------------------------------------
Original description (Deflandre and Cookson, 1955):

Palaeohystrichophora minuta sp. nov.
Fig. 4

Upper Cretaceous (Senonian): Gingin, W.A.
Theca biconical with slightly convex sides; transverse girdle relatively wide and shallow; epitheca and hypotheca approximately equal, epitheca prolonged into a short, cylindrical, truncate process, hypotheca terminating in a short, sharp point. Membrane without trace of plates rather sparsely clothed with short, irregularly disposed spines.
Dimensions. - Length 40 μ, breadth 26 μ.
The single specimen on which this species is based (holotype) is at present the smallest of the Australian Cretaceous dinoflagellates.