796


Journal of Paleontology 92(5):794–803


(e.g., Dance and Poppe, 1999; Merle and Pacaud, 2004) recognized only Morum. Other workers (e.g., Beu, 1976; Emerson, 1981, 1990;Vokes, 1998) usedOniscidia as a subgenus ofMorum.Only a fewworkers (e.g.,MacNeil andDockery, 1984; Garvie, 2013) used Oniscidia as a separate genus. Oniscidia Mörch differs from Morum by having a more lightweight shell that is cylindrical/tubular, much more extended


(never fat) spire, much narrower spire angle, subsutural collar, much finer axial and spiral sculpture (no broad nodular spiral bands), cancellate sculpture very common, better developed siphonal fasciole, and presence of denticles on outer lip varix exterior. Oniscidia differs from Eocithara by having a subsutural


collar, granules on the columellar shield, more closely spaced axial ribs with interspaces not smooth, stronger spiral ribs which can be cancellate or finely nodose, shorter siphonal fasciole, thicker outer lip, and presence of denticles on outer lip varix exterior and interior. Oniscidia differs from Harpa by having a shell that is not


glossy, much less inflated last whorl, subsutural collar, much less widely spaced axial ribs and being neither flat nor smooth, spiral ribs present and can be cancellate, columellar shield present,much shorter and less-developed siphonal fasciole, much narrower aperture, and thicker outer lip with varix bearing denticles. Onisicidia differs from Austroharpa by having a thicker


shell that is neither as inflated nor nearly smooth, subsutural colar, much thicker axial ribs, non-bulbous protoconch not bulbous, less-developed siphonal fasciole, and thicker outer lip with stronger denticles. Known fossil species of Oniscidia are listed in Table 1.


Figure 2. Stratophenic interpretation of subfamilies and genera of Harpidae. Geologic range information sources: herein for Oniscidia; Hughes and Emerson (1968) for Morum; Merle and Pacaud (2004) for Eocithara, Harpa, and Austroharpa.


Remarks.—The name “Oniscidia Sow.” first appeared in Swainson (1840, p. 299, fig. 66c), who gave a description and illustration, both of which apply to Morum onicus Linnaeus, 1767, the type species of Morum. It seems likely that Swainson intended to use the name Oniscia Sowerby, 1825, which is a junior synonym of Morum, because, in the “index” section of his article, Swainson (1840, p. 414) only listed Oniscia.There was enough subsequent confusion, however, concerning the taxonomic status of Oniscidia to justify a ruling (Opinion 1040) by the ICZN (1975, p. 139). The outcome was that Oniscidia Swainson, 1840 is deemed to be “an incorrect subsequent spelling for Oniscia Sowerby.” In addition, it was ruled that Oniscidia Mörch, 1852 is an official generic name. Mörch used Oniscidia cancellata Sowerby, G.B., I., 1825 as the type species, which encompasses harpid species characterized by their triangularly ovate shape, extended spire, and cancellate sculpture. For addi- tional discussions and comments concerning the complicated taxonomic history of Oniscidia Swainson (1840), the reader is referred to Dall, (1909, p. 67), Dodge (1956, p. 267), Woodring (1959, p. 202),MacNeil and Dockery (1984, p. 112), Hughes and Emerson (1987, p. 357), and Vokes (1998, p. 17). Taxonomic inconsistencies regarding Oniscidia Mörch and Morum have continued to modern times. Some workers


Based on the comments by Dall (1909, p. 69), the earliest representative of this genus is questionably Oniscidia costellata (Stoliczka, 1867, p. 63, pl. 5, figs. 9, 9a, 9b), from an Upper Cretaceous deposit south of Aryalur (Arialoor), southern India. Stoliczka’s sketches are not as clearly revealing as they could be, but his species has some Oniscidia features: long aperture, outer lip varix whose interior is denticulate, a produced siphonal canal that is recurved, prominent axial ribs, and spiral ribs. Dall (1909) noted that Stoliczka’s species does have a more extended spire than later representatives of this genus, but its spire height is similar to the extant Oniscidia cancellata (Sowerby, 1825) and Oniscidia macdonaldi (Emerson, 1981). Stoliczka’s species does have a narrower spire angle than most species of Oniscidia, but the spire angle of the extant Oniscidia matthewsi (Emerson, 1967) is similar. Additional specimens of Stoliczka’s species might establish positively that it is the earliest fossil record of


Oniscidia. Using the information from Sundaram et al. (2001, figs. 3, 5), this species is most likely from the Upper Cretaceous (Campanian) Sillakkudi Formation. “Scala cf. subtenuilamella” d’Archiac and Haime, 1854,


illustrated by Cossmann and Pissarro (1927, p. 75, pl. 7, fig. 20), questionably belongs to Oniscidia. This specimen is part of a diverse assemblage of mollusks described by Cossmman and Pissarro (1927) and determined to be of earliest Eocene age from the Lakhara Formation (part of the Ranikot Group) in southern Pakistan (Merle et al., 2014). The specimen resembles Oniscidia by having strong axial ribs, which are swollen posteriorly, and a subsutural collar. The anterior part of the last whorl is missing; therefore, this potential new species can only be questionably assigned to Oniscidia.


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