Original Description of Rostellaria unidigitata by Newton, 1922:
- "Shell robust, pyramidial above, oblong below, depresso-convex; body-whorl excavated at suture, obtusely margined, compresso-convex, oblong, length exceeding that of the spire, canaliculated anteriorly and in rear; spire with seven or eight high and laterally depressed whorls, suture deep, nuclear whorls smooth and obtusely apexed; surface with strong spiral bands divided by longitudinally striated grooves, earlier whorls, excluding the nuclear whorls, furnished with numerous vertical placations, and obscure varices, body-whorl more or less smooth, finely and microscopically striated in both directions in nearly half its length, whilst the base is strongly and spirally ornamented; aperture obliquely elliptical, widely notched below and narrowly canaliculated at each end, the posterior canal is directed backward from the front along the sutural platform; labrum smooth within, border posteriorly excavated and outwardly curved below, thick, with wide reflective lip, which forms a single spinose digitations in front, afterwards surrounding the notch, and similarly the inner side of the narrow, curved, anterior canal; columella smooth, excavated, covered with a strong callosity which is elevated, thick and much enameled posteriorly where it forms the inner boundary of the canal, which thins out at the angle and extends along the sutural cavity of the body-whorl, besides forming part of the recurved posterior canal."
Locus typicus: Ameki, Omobialla District, Nigeria
Lectotype: R.B. Newton, 1922 pl. 4 fig. 3, designated by F.E. Eames, 1957, 3.
no. G.41688 (British Museum of Natural History)
Cyrtulotibia unidigitata (Newton, 1922); Lectotype; upper Lutetian, Eocene; Ameki, Omobialla District, Nigeria; Coll. BM(NH) no. G.41688; Copyright BM(NH)
Cyrtulotibia unidigitata (Newton, 1922); upper Lutetian, Eocene; Ameki, Omobialla District, Nigeria; Coll. BM(NH) no. G.41670; Copyright BM(NH)
Cyrtulotibia unidigitata (Newton, 1922); upper Lutetian, Eocene; Ameki, Omobialla District, Nigeria; Coll. BM(NH) no. G.416689-91; Copyright BM(NH)