The genotype of Parafusulina Dunbar & Skinner, 1931is the species Parafusulina wordensis Dunbar & Skinner, 1931, by original designation (Dunbar and Skinner 1931: 259). The type specimens of P. wordensis are reposited in the Invertebrate Paleontology collection of the Peabody Museum of Natural History, Yale University, New Haven, CT, USA (White and Skorina 2003). As Dunbar & Skinner (1931) did not designate a holotype for P. wordensis from their syntype suite, Thompson (1948: 54)selected the specimen figured in Plate 72, figure 5 of Dunbar and Skinner (1937)as the “holotype,” or more accurately the lectotype. The following catalogue numbers have been assigned to the type specimens of Parafusulina wordensis: YPM 21145 (paralectotype), YPM 50046 (paralectotype), YPM 50047 (paralectotype), YPM 20885 (paralectotype), YPM 20886 (lectotype), YPM 20887 (paralectotype), YPM 20888 (paralectotype), YPM 25265 (paralectotype), YPM 25266A (paralectotype), and YPM 25266B (paralectotype).
The genus Parafusulina was first described by Dunbar & Skinner (1931) based on fossil specimens collected from the Guadalupian-aged (Middle Permian) Word Formation in the Glass Mountains, Texas, U.S.A. Dunbar & Skinner’s (1931: 258) original description is as follows:
“Shells elongate-fusiform to subcylindrical, commonly attaining a large size. The wall is alveolar, consisting of a tectum and keriotheca. The septa are very evenly and strongly fluted from pole to pole, the opposed folds of adjacent septa being united near their base so as to subdivide the meridional chambers into a series of cell-like chamberlets. A low equatorial tunnel is generally present but in some of the more highly specialized species is lacking. Each septum is perforated by a row of regularly arranged basal foramina, each opening being at the extremity of one of the septal folds. Each foramen is really an arch formed by the upbending and union of the basal margin of the forward fold of one septum with the backward fold of the next. Each chamber is thus in direct connection with the second beyond. The basal margins of adjacent septa are joined along the sides of the chamberlets so as to form a series of wavy spiral sutures where they join the floor of the volution (Fig. 4, Plate II). Thus the juncture of the septa with the roof of the volution is axial and that with the floor spiral. Neither chomata nor parachomata are present. Septal pores have not been observed and are probably not present.”
