Paracratis borealis (Jeffreys, 1869)

Paracratis borealis (Jeffreys, 1869) View in CoL revalidated, new combination ( Fig. 48F View Figure 48 )

Limopsis borealis Jeffreys, 1869: 174-175 View in CoL .

Limopsis minuta View in CoL : Maury, 1920: 43; Poirier, 1954: 148; Rios, 1975: 195 (pl. 62, fig. 952), 1985: 211 (pl. 76 fig. 1075), 1994: 233 (pl. 81, fig. 1152), 2009: 478 (fig. 1345); Gofas et al., 2001: 206; Janssen & Krylova, 2014: 56; Janssen, 2015: 16, 25; Molluscabase, 2024; Passos et al., 2024: 28 View Cited Treatment (non Philippi, 1836).

Type localities: 50 miles N of Hebrides, 189 fms. E Nordland, 70-100 fms. Upper Norway, 450 fms.

Remarks: Paracratis borealis ( Fig. 48F View Figure 48 ) has previously been identified as Limopsis minuta , described by Philippi as Pectunculus minutus in 1836 (pg. 63, pl. 5, fig. 3) ( Fig. 48E View Figure 48 ). This species was initially described from the Plio-Pleistocene deposits in Sicily, Italy (Mediterranean). It has been reported as present in the Recent period from Canada to Mexico, with some disjunct occurrences in South Brazil ( e.g., Rios, 2009).

Despite the significant temporal and regional differences, which might suggest a strong case for specific separation, Limopsis minuta , as described and illustrat- ed by Philippi (1836), still exhibits conchological distinctions ( Fig. 48E View Figure 48 ). It is notably larger, reaching around 15 mm, whereas P. borealis measures approximately 6 mm. Furthermore, Limopsis minuta features a more arched hinge and a taller umbo compared to those of P. borealis ( Fig. 48F View Figure 48 ). The shell outline is also much less inclined (around 80°), while P. borealis has an angulation of approximately 65°.

Based on these temporal, geographic, and morphological differences, the most appropriate taxonomical procedure is to maintain Limopsis minuta as a Plio-Pleistocene Italian fossil within the genus Paracratis . Concurrently, its previous synonym, P.borealis , should be revalidated to represent the Recent Atlantic species.