Lepidopleurus pseudocajetanus Dell'Angelo, Sosso & Taviani, 2025, sp. nov.
Lepidopleurus pseudocajetanus sp. nov. Fig. 6 Lepidopleurus (Lepidopleurus) cajetanus [non Lepidopleurus cajetanus (Poli, 1791)]; Dell’Angelo & Palazzi 1989, p. 45, pl. 2. Lepidopleurus cajetanus [non Lepidopleurus cajetanus (Poli, 1791)]; Dell’Angelo et al. 2013, p. 68, pl. 1, figs D–E; Dell’Angelo et al. 2015a, p. 220, pl. 1, fig. 5; Dell’Angelo et al. 2021b, p. 407, figs 4–7. Type material. Holotype: MSNG 62623, intermediate valve, width 9.5 mm (Figs 6F–H). Paratype 1: MSNG 62624, intermediate valve, width 8 mm (Figs 6A–C), from Saint-Clément-de-la-Place, France, Miocene (Tortonian). Paratype 2: MNHN.F.A98468, intermediate valve, width 6.5 mm (Figs 6D–E), from Rio S. Antonino (Italy), Pliocene (Zanclean). Paratype 3: SMF 380817, intermediate valve, width 7 mm, from Bussana (Italy), Pliocene (Zanclean). Paratype 4: NHMW 1861/0028/0079 (as Lepidopleurus decoratus), intermediate valve, width 9 mm (Figs 6I–L), from Pötzleinsdorf (Austria), Middle Miocene. Type locality. Pezzo, near Villa S. Giovanni (Calabria, Italy). Type stage. Upper Pleistocene, but presumably originated from contiguous deposits of the Lower Pleistocene of bathyal facies. Etymology. The name recalls the morphological resemblance with the extant species Lepidopleurus cajetanus. Material examined. Middle Miocene: Central Paratethys: Austria: Pötzleinsdorf, type material. Upper Miocene: France, Ligerian Basin (Tortonian): Anjou: Saint-Clément-de-la-Place: type material plus 4 valves (BD 312). Italy, Po Basin (Tortonian): Borelli: 2 valves (BD 313), Montegibbio: 1 valve (BD 314), Rio di Bocca d’Asino: 3 valves (BD 315). Lower Pliocene: Italy: Liguria: Borzoli: 26 valves (BD 316), Bussana: 17 valves (BD 317), Genova Sestri: 2 valves (BD 318), Rio S. Antonino: 2 valves (BD 319). Pliocene: Italy: Tuscany: Pietrafitta: 1 valve (BD 320), Serre di Rapolano: 10 valves (BD 321), Stroncoli: 4 valves (BD 322); Emilia-Romagna: Bacedasco: 3 valves (BD 323), Vernasca: 1 valve (BD 324). Pleistocene: France: Corsica: Patrimonio: 2 valves (BD 325). Italy: Emilia-Romagna: Torrente Stirone: 4 valves (BD 326); Puglia: Punta Penne: 2 valves (BD 327); Calabria: Archi San Francesco: 4 valves (BD 328), Le Castella: 2 valves (BD 329), Pecoraro: 1 valve (BD 330), Pezzo: type material plus 4 valves (BD 331). Maximum width of the valves: 9.5 mm (intermediate). Diagnosis. Head and tail valves unknown. Intermediate valves solid, broadly rectangular, rounded, highly elevated, apex not evident, lateral areas triangular, originating from posterior margin, very angled. Tegmentum coarse, very variable, LA sculptured with strong, concentric, terraced ribs, CA with longitudinal chains of granules, somewhat branching or anastomosing. Granules of irregular shape, elevated, united with each other, with one subcentral megalaesthete and some micraesthetes. Articulamentum without insertion laminae, apophyses small, triangular. Description. Head and tail valves unknown. Intermediate valves solid, broadly rectangular, with a very variable width/length ratio, rounded in anterior profile, highly elevated (H/W = 0.40–0.64), anterior margin straight or slightly convex between apophyses, lateral margins slightly rounded, posterior margin very irregular, convex, apex not evident, lateral areas triangular, more irregular and sometimes slightly curved, originating from posterior margin, forming an angle from 50-60° upwards, up to almost perpendicular. Tegmentum coarse, very variable, LA sculptured with strong, concentric, terraced ribs, more or less spaced from each other, CA with longitudinal chains of granules, somewhat branching or anastomosing, transversally intersected by much thinner cords that give a pitted appearance. Granules of irregular shape, from roundish to polygonal, elevated, united with each other, with one subcentral megalaesthete and some micraesthetes. Articulamentum without insertion laminae, apophyses small, triangular, divided by a wide jugal sinus. Remarks. Lepidopleurus pseudocajetanus sp. nov. is characterized by intermediate valves [attributed to L. cajetanus (Poli, 1791) by previous authors] showing the starting point of LA with the concentric terraced ribs neighbouring the lateral margin (not near the apex), much more angled at the posterior margin, from 50-60° upwards up to almost perpendicular, rounded in anterior profile but more elevated (H/W = 0.40-0.64), which give the valves a very different look to that of L. cajetanus. The posterior margin is also very irregular, not straight but convex, as if there were real “shortcomings” (Figs 6A, 6D, 6I), which however cannot be detected by an examination of the articulamentum, and with no trace of the apex. Similarly, the apical area is thicker, it does not tend to thin towards the ends of the posterior margin as in L. cajetanus, but projects towards the end of LA (Figs 6B, 6G). Some of these valves have already been photographed and published as L. cajetanus (Dell’Angelo & Palazzi 1989; Dell’Angelo et al. 2013, 2015a, 2021b). Intermediate plates of both species (Lepidopleurus cajetanus and L. pseudocajetanus sp. nov.) co-occur in some of the locations examined, including the Paratethys. Comparisons. See Tab. 1 for a comparison with the Lepidopleurus spp. considered in the present study. Distribution. Middle Miocene: Central Paratethys (Langhian-Serravallian): Austria; Pötzleinsdorf (this study). Upper Miocene: northeastern Atlantic: France: Saint-Clément-de-la-Place, (this study); Proto-Mediterranean Sea: Po Basin, N Italy: Borelli, Montegibbio, Rio di Bocca d’Asino (this study). Lower Pliocene: central Mediterranean, Italy: Liguria: Borzoli, Bussana, Genova Sestri, Rio S. Antonino (this study). Pliocene: central Mediterranean, Italy: Bacedasco, Pietrafitta, Serre di Rapolano, Stroncoli, Vernasca (this study). Pleistocene: central Mediterranean, France: Corsica: Patrimonio (this study); Italy: Archi S. Francesco, Le Castella, Pecoraro, Pezzo, Punta Penne, Torrente Stirone (this study).
Institutions
- Istituto di Scienze Marine del Consiglio Nazionale delle Ricerche (IT)
- University of Bengkulu (ID)
- University of Genoa (IT)
Publication Details
- Journal
- Zenodo (CERN European Organization for Nuclear Research)
- Published
- 2025-10-08
- DOI
- https://doi.org/10.5281/zenodo.17327770
- Primary Topic
- Retinal Development and Disorders
- Type
- article
- Field-Weighted Citation Impact
- 0.00