Lepidochitona rochae, Dell'Angelo, Landau, C. M. D. Silva & Sosso, 2022

Lepidochitona rochae View in CoL Dell’Angelo, Landau, Silva & Sosso, 2022

Fig. 120 View FIGURE 120

Lepidochitona rochae View in CoL Dell’Angelo, Landau, Silva & Sosso, 2022, p.16, fig. 9.

Type material. Holotype RGM.1364017, intermediate valve, width 2.3 mm ( Figs120A–D View FIGURE 120 ). Paratype RGM.1364018, intermediate valve (width 4.8 mm).

Type locality. Vale de Freixo site, near the village of Carnide, Pombal municipality (central-west Portugal) .

Type stage. Pliocene, upper Zanclean to lower Piacenzian, Carnide Formation, basal fossiliferous grey sands, “Bed 3” in Gili et al. (1995) and Dell’Angelo & Silva (2003).

Material examined. Pliocene: Portugal: Vale de Freixo : type material plus 14 intermediate valves: ( BD 245 , GeoFCUL VFX.03.361, Figs 120E–H View FIGURE 120 , GeoFCUL VFX.03.344–VFX.03.345, RGM.1364019, MNHN.F. A81991 View Materials ). Maximum width 4.8 mm .

Description. Head and tail valves unknown. Intermediate valves broadly rectangular (W/L = 2.70–2.90), elevated (H/W = 0.40–0.50), carinate in anterior profile, anterior margin convex with jugal part almost straight, side margins slightly rounded, posterior margin straight or slightly concave on both sides of large and prominent apex, lateral areas slightly raised, sharply delimited.

LA sculptured with fine elongate granules, coalescing into continuous, radially oriented lines, few concentric growth lines more evident towards side margins. CA covered for about 60% of valve width by roundish irregular granules, almost all separated, but some coalescent, with up to eight aesthetes of equal size; 40% continuing towards side margins by obliquely oriented and few concentric growth lines joined with those present on lateral areas. Each granule with up to 8 aesthetes of equal size in CA.

Articulamentum with poorly preserved apophyses, round, apical area triangular, insertion plate short with two slits, slit ray well visible (second slit ray lies close to posterior margin).

Remarks. The fossil record of Lepidochitona rochae Dell’Angelo, Landau, Silva & Sosso, 2022 is limited to the Pliocene of Portugal, based upon of a few intermediate valves, incomplete and poorly preserved. However the generic attribution has ben problematic, and the species was assigned to Lepidochitona mainly based on the similarity of the granules in the central area of the valves with the sculpture typical of this genus.

Comparisons. Lepidochitona rochae is well characterized by the granules of the tegmental sculpture covering only a part of the whole valve.

Distribution. Pliocene: Northeastern Atlantic, Mondego Basin, Portugal: Vale de Freixo ( Dell’Angelo et al. 2022).