Original Description of Rostellaria bidigitata by Newton, 1922:
- "Shell thick, elongate, narrowly pyramidal, turriculate, depresso-convex; body-whorl compresso-convex, postero-dorsally inflated, canaliculated anteriorly and in rear; spire produced, comprising about ten deep, flattened whorls, divided by a deep slightly excavated suture; surface of the earlier whorls spirally striate and longitudinally plicated, the later whorls smother although retaining a somewhat similar sculpture of closely set spiral striations crossed by a numerous longitudinal and more or less sinuous lineations, the union of which produces a marked reticulation at the base; aperture narrow longitudinally and obliquely elliptical, widely notched at the base followed by a straight, narrow canal; labrum smooth within, furnished with a thick reflected nearly perpendicular margin bearing two distant spinose digitations, the lowest forming the posterior end of the notch; columella smooth, obliquely excavated, covered with a prominent enameled callosity which becomes elevated into a thickened tubercle posteriorly where it forms the lateral boundary to a narrow canal in conjunction and parallel with the labrum."
Locus typicus: Ameki, Omobialla district, South Nigeria
Stratum typicum: upper Lutetian, Eocene
Lectotype: R.B. Newton, 1992 pl. 4 fig. 8, designated by F.E. Eames, 1957, 36.
G.41643 (British Museum Natural History)
Tibia bidigitata (Newton, 1922); Lectotype; upper Lutetian, Eocene; Ameki, Omobialla district, E. Nigeria; Coll. BM(NH) no. G 41643; Copyright BM(NH)
Tibia bidigitata (Newton, 1922); upper Lutetian, Eocene; Ameki, Omobialla district, E. Nigeria; Coll. BM(NH) no. G 41644-5; Copyright BM(NH)
Tibia bidigitata (Newton, 1922); upper Lutetian, Eocene; Ameki, Omobialla district, E. Nigeria; Coll. BM(NH) no. G 41649; Copyright BM(NH)