Fasciculicardia, Maxwell, 1969

Pérez, Damián E. & Del Río, Claudia J., 2017, Systematics of the family Carditidae (Bivalvia: Archiheterodonta) in the Cenozoic of Argentina, Zootaxa 4338 (1), pp. 51-84 : 66

Fasciculicardia sp.

Figure 5.1–2

.1942 Venericardia paranensis Borchert—Wahnish de Carral Tolosa , p. 575, pl. 1, figs. 4a–b.

.vp1991 Venericardia ( Purpurocardia ?) paranensis Borchert—del Río, p. 60, fig. 6, fig-text 20.

Studied material. MACN-Pi 361b (one left valve).

Remarks. Del Río (1991) described two left valves from the Ihering Collection as V. (P?) paranensis from La Paz. The two shells have different sculptures and del Río interpreted them as different ontogenetic stages of a single species. However, both valves are of similar size. The first one (MACN-Pi 361b) is characterized by a small and nearly vertical lunule, very small left anterior tooth inclined posteriorly, left posterior tooth elongate and narrow, 26 high sharp radial ribs with subtriangular transverse sections, more pronounced towards anterior margin, no paracostal ribs, narrow and serrated nodes, small tubular spines along posterior margin and very wide intercostal spaces with ‘U’-shaped transverse sections. These characters agree with Fasciculicardia and allow this species to be assigned to Fasciculicardia sp. The incompleteness of the shells prevents comparison with other Fasciculicardia species. Wahnish de Carral Tolosa (1942) described a small specimen of Venericardia paranensis ( Borchert, 1901) from the Monte Veloz perforation (“Entrerriense” horizons, upper Miocene, Buenos Aires Province) that could be considered as belonging to Fasciculicardia sp.

The other specimen described by del Río (1991) (MACN-Pi 361a) belongs to the planicostate carditid Neovenericor paranensis ( Borchert, 1901) ( Pérez et al. 2017a).