Pyxidinopsis "protospinosus" Zevenboom and Santarelli in Zevenboom, 1995, p.154, pl.9, figs.4–8. Holotype: Zevenboom, 1995, pl.9, figs.7–8. Name not validly published: considered a manuscript name. The epithet is correctly rendered as "protospinosus", not "protospinosis". Age: late early Miocene–earliest middle Miocene.

Original description (Zevenboom, 1995)
Manuscript holotype: Sample Crt 41/1, EF (X44/3), Plate IX, 5-7
Manuscript paratype: Sample Cassa 39/1 EF, (N33/1), Plate IX, 4, 8.
Etmology: In reference to the superficial resemblance to Pyxidinopsis spinosis Zevenboom and Santarelli and its occurence earlier in time.
Type locality: Cortemilia section, Tertiary Piedmont Basin, North Italy.
Type stratum: Cassinasco Formation.
Diagnosis: A species of Pyxidinopsis characterized by its small size and its short solid semi-conical processes.
Dimensions: Height: 40(43)45 µm; Width: 35(38)40µm; Processes: 2-3 µm; Reticulum: 2-3µm; Wall thickness: 2-3 µm. N=15 specimens measured.
Description: A subspherical species of Pyxidinopsis characterized by its small size. The endo- and periphragm are appressed. The periphragm forms a reticulum of low relief, from which short, solid blunt spines arise. On some specimens the reticulum is reduced, or lacking altogether. The archaeopyle is formed by the loss of paraplate 3", operculum free.
Discussion: Pyxidinopsis protospinosus differs from Pyxidinopsis spinosis Zevenboom and Santarelli, by its smaller size and its rounder overall shape and in the possession of a reticulum which give rise to the short, blunt, solid processes.
Occurrence: Italy (Biffi and Manum, 1988 and this study)
Total stratigraphical range: Late Early Miocene to earliest Middle Miocene (this study)