Palaeohystrichophora palaeoinfusa Fensome et al., 2009, p.51, pl.8, figs.q–t.
Holotype: Fensome et al., 2009, pl.8, fig.r.
Age: youngest occurrence (frequent), middle Cenomanian.

Original description (Fensome et al.,2009)
Holotype: Plate 8, fig. r; from a sidewall core sample at 1552.0 m (5092 feet) in Onondaga E-84 well; GSC type
collection no. 130274, sample P37533, slide 01, co-ordinates 10.1 × 92.0, England Finder J35/3;
Age: (middle) Cenomanian (Late Cretaceous).

Description:
A species of Palaeohystrichophora with a central body that has a peridinioid shape - i.e. there are two antapical horns, typically asymmetrically disposed.

Dimensions:
Overall length 59(66)75μm, overall width 37(46)50μm, endocyst length 35(41)44μm, endocyst width 37(43)49μm, length of spines up to 4(5)6μm; 6 specimens measured. Holotype: overall length 75μm, overall width 48 μm, endocyst length 44 μm, endocyst width 44μm, length of spines up to 4μm.

Remarks:
This species differs from Palaeohystrichophora infusorioides in having a peridinioid, rather than a fusiform shape.