Acanthochitona crinita ( Pennant, 1777 )

Acanthochitona crinita ( Pennant, 1777) View in CoL

Fig. 134 View FIGURE 134

Chiton crinitus Pennant, 1777, p. 71 , pl. 36, figs 1, A1.

Chiton fascicularis [non Acanthochitona fascicularis ( Linnaeus, 1767) View in CoL ]; Seguenza 1874, p. 12; Nobre 1892, p. 25; Malatesta 1943, p. 165, 167, 178; Comaschi Caria 1955, p. 231; Comaschi Caria 1958, p. 149

Anisochiton fascicularis View in CoL [non Acanthochitona fascicularis ( Linnaeus, 1767) View in CoL ]; B.D.D. 1882, p. 505.

Acanthochites fascicularis View in CoL [non Acanthochitona fascicularis ( Linnaeus, 1767) View in CoL ]; Monterosato 1879, p. 28; Coppi 1881, p. 87

Acanthochitona fascicularis View in CoL [non Acanthochitona fascicularis ( Linnaeus, 1767) View in CoL ]; Seguenza 1883, p. 90; Malatesta 1962, p. 164, figs 22–23; Ruggieri & Greco 1965, p. 53; Moroni 1967, p. 143; Ruggieri 1967, p. 314; Di Geronimo 1969, p. 211; Buccheri 1970, p. 245, 255; Greco 1970, p. 293; Buccheri & Greco 1971, p. 196; D’Alessandro 1971, p. 383; Greco et al. 1974, p. 171; D’Alessandro & Laviano 1975, p. 125; Laghi 1977, p. 111, pl. 3, figs 20–21; Sabelli & Taviani 1979, p. 161, pl. 1, fig. 15; Di Geronimo 1979, p. 47; Ruggieri 1982b, p. 260; Bałuk, 1984, p. 291, pl. 9, fig. 2 ( fide Bałuk 1984); Crovato & Taviani 1985, p. 292; Zanaroli 1985, table 2; Studencka & Studencki 1988, p. 41, pl. 4, fig. 1–2 ( fide Studencka & Dulai 2010); Tabanelli & Segurini 1994, p. 7; Bellomo & Sabelli 1995, p. 201.

Acanthochiton aff. fascicularis View in CoL [non Acanthochitona fascicularis ( Linnaeus, 1767) View in CoL ]; Šulc 1934, p. 19 (= A. lacrimulifera , fide Bałuk 1984).

Acanthochitona crinita ( Pennant, 1777) View in CoL ; Laghi 1984, p. 556; Kaas 1985a, p. 588, figs 7–50; Cavallo & Repetto 1992, p. 30, fig. 4 Dell’Angelo & Forli 1995a, p. 236, fig. 13; Giani 1998, p. 116, pl. 43, fig. 4; Dell’Angelo & Smriglio 1999, p. 198, pls 66–68, figs 124–130; Dell’Angelo et al. 1999, p. 275, pl. 5, figs 2, 6; Mancini 1999, p. 20; Dell’Angelo & Giusti 2000, p. 56, fig. 11; Dell’Angelo et al. 2001a, p. 153, fig. 32; Forli et al. 2003, p. 152; Chirli 2004, p. 16, pl. 6, figs 7–8; Dell’Angelo et al. 2004, p. 40, pl. 4, figs 2, 5; Puchalski et al. 2008 (database: chiton fossil records); Koskeridou et al. 2009, p. 322, figs 11.1–11.2; Sosso & Dell’Angelo 2010, p. 15, unnumbered fig. p. 17; Strack 2010, p. 64, fig. 58–59; Bonfitto et al. 2011, p. 173, figs 2, 4B, 6B; Dell’Angelo et al. 2012, p. 63, fig. 6C; Dell’Angelo et al. 2013, p. 96, pl. 10, figs H–M; Schmidt-Petersen et al. 2015, p. 17, figs 5–6, tab. 1; Dell’Angelo et al. 2016, p. 88, pl. 5, figs 12–18, pl. 6, figs 1–2; Brunetti & Cresti 2018, p. 28, fig. 9a–b; Dell’Angelo et al. 2018b, p. 41, 46, tab. 14, 17; Dell’Angelo et al. 2020b, p. 39, figs 25.A–B, 25.D–L ( non fig. 25.C = Acanthochitona sp. ); Dell’Angelo et al. 2021b, p. 427, figs 158–161; Dell’Angelo et al. 2022, p. 17, fig. 10; Brunetti & Cresti 2023, p. 10.

Acanthochitona lacrimulifera Bałuk, 1971, p. 484 , pl. 2, figs 6–9; Laghi 1977, p. 111; Bałuk & Radwanski 1979, p. 231; Studencka & Dulai 2010, p. 268; Dulai 2025a, p. 11, figs 19–21); Dulai 2025b, p. 30, figs 20–22).

Type material. Neotype RSMNH 1978.052.02601, designated and figured by Kaas (1985a: p. 591, fig. 27).

Type locality. Hebrides Islands, Monach Island , North Uist, U.K.

Material examined. Lower Miocene: France (Aquitanian): Lariey: 2 valves ( JFL); France (Burdigalian): Coupe du fossé près de La Solitude: 1 valve ( JFL), Gamachot: 58 valves ( AC, BD 961, JFL, PR, MZB 50580– 50582, Figs 134B–D, 134J–L View FIGURE 134 ), Maureilhan: 37 valves ( BD 962, Fig. 134A View FIGURE 134 ), Petit Bargues: 1 valve ( JFL); Italy (Burdigalian): Sciolze: 5 valves ( PG), Valle Ceppi: 1 valve ( BD 963). Middle Miocene: France (Serravallian): Orthez: 1 valve ( BD 964); Sallespisse Carré: 1 valve ( DA); Italy (Langhian): Albugnano: 10 valves ( BD 965, MZB 32108–32109, Figs 134E–F View FIGURE 134 , PG). Upper Miocene: Italy (Tortonian): Borelli: 2 valves ( MGPT, MZB 32113), Montegibbio: 11 valves ( BD 966, MZB 32112), Rio di Bocca d’Asino: 23 valves ( BD 967, MZB 32110-32111, PG). Lower Pliocene: Italy: Borzoli: 67 valves ( BD 968), Bussana: 252 valves ( BD 969, Fig. 134I View FIGURE 134 , MZB 45767, Figs 134G–H View FIGURE 134 , SR), Caranchi: 8 valves ( BD 970, MP), Garlenda: 6 valves ( MP, MZB 45766), Genova Sestri: 22 valves ( BD 971), Rio Sant’ Antonino: 105 valves ( BD 972), Rio Torsero: 5 valves ( BD 973, MZB 45768), Zinola: 1 valve ( BD 974). Pliocene: Portugal: Vale de Freixo: 42 valves ( BD 246, GeoFCUL VFX.03.347, GeoFCUL VFX.03.362–363, RGM.1364020–1364021, MNHN.F. A81992 View Materials ). Spain: El Papiol: 5 valves ( BD 975); Estepona: 11 valves ( BD 976); Italy: Piedmont: Baldichieri: 1 valve ( BD 977), Montafia: 7 valves ( BD 978), Vintebbio: 3 valves ( BD 979); Emilia-Romagna: Cava di Campore: 20 valves ( BD 980), Gagliardella “Tagliata”: 3 valves ( BD 981); Tuscany: Bibbiano: 3 valves ( BD 982), Castiglioncello del Trinoro: 1 valve ( BD 983), Colle Val d’Elsa: 2 valves ( BD 984), Montenero: 1 valve ( BD 985), Orciano Pisano: 7 valves ( BD 986), Pietrafitta: 15 valves ( BD 987), Serre di Rapolano: 4 valves ( BD 988); Latium: Magliano Sabina: 1 valve ( BD 989); Sicily: Altavilla: 1 valve ( BD 990), Trappeto: 13 valves ( BD 991). Pleistocene: Italy: Emilia-Romagna: Torrente Stirone: 4 valves ( BD 992); Tuscany: Capraia Island-Capo Corso -350/ 500m: 5 valves ( BD 993), Cisternino: 2 valves ( BD 994), Fauglia: 3 valves ( BD 995), Riparbella: 25 valves ( BD 996); Puglia: Gallipoli: 3 valves ( BD 997); Calabria: Archi S. Francesco: 12 valves ( BD 998), Carrabbati: 10 valves ( BD 999), Gallina: 4 valves ( BD 1000), Musalà: 1 valve ( BD 1001), Pecoraro: 7 valves ( BD 1002), Petti di Carrubbare: 2 valves ( BD 1003), Pezzo: 4 valves ( BD 1004), San Procopio: 3 valves ( BD 1005), Stalettì: 1 valve ( BD 1006) Vito Superiore: 1 valve ( BD 1007); Sicily: Ficarazzi: 1 valve ( BD 1008), Salice: 1 valve ( BD 1009). Maximum width of the valves: 3.5 / 6 / 4.2 mm.

Description. Head valve semicircular, posterior margin straight, slope slightly convex. Intermediate valves broadly rectangular (WT/LT = 1.43–1.70), rather elevated (H/W = 0.40–0.48), semicarinate in anterior profile, anterior margin straight between apophyses, lateral margins whose partly straight and partly rounded profile gives the valve a nearly pentagonal shape, posterior margin almost straight on both sides of pronounced apex, jugal area longitudinally striated, raised, not well separated from lateropleural area. Tail valve elliptical to circular (WT/LT = 1.16–1.35), jugal area longitudinally striated, raised, mucro well evident in subcentral to slightly posterior position, postmucronal area rather reduced, antemucronal slope slightly convex, postmucronal slope concave behind mucro.

Whole tegmentum (except JA) sculptured with moderatly widespread, roundish/oval to drop or pear shaped granules, elevated, with flat or slightly concave surface, arranged along arched lines, jugal area longitudinally striated; granules of variable size, 1–2 times as long as wide, maximum size 194 μm, with a single posteriorly located megalaesthete and many micraesthetes, ranging from 12 to over 16, irregularly grouped mainly in anterocentral part of granules.

Articulamentum well developed, apophyses quadrangular and strongly protruding, delimiting a wide jugal sinus, expanded and completely surrounding tail valve, except for jugal margin, slit formula 5 / 1 / 2.

Remarks. Acanthochitona crinita ( Pennant, 1777) was reported by most Authors as A. fascicularis (non Linnaeus, 1767) before the work of Kaas (1985a). Acanthochitona crinita is an extremely variable species with a complicated synonymy. The size and shape of the granules are highly variable, more or less drop-shaped or tending to an oval profile.

Dell’Angelo et al. (2018a) attributed tentatively to Acanthochitona crinita a single valve from the upper Oligocene (Chattian) of Saint-Etienne-d’Orthe ( France, Aquitaine Basin). The scantness of material (1 valve) and geological antiquity makes highly unlikely its cospecificity with the extant taxon.

Acanthochitona lacrimulifera Bałuk, 1971 , from the Paratethys of Poland was interpreted as a direct ancestral form of the Recent A. crinita View in CoL (by Bałuk 1971, as A. fascicularis View in CoL ), but as a synonym of A. crinita View in CoL by all subsequent authors ( Laghi 1977 and Bałuk 1984 as A. fascicularis View in CoL ; Dell’Angelo et al. 1999; Studencka & Dulai 2010). Dulai (2025a) considered Bałuk (1971) ’s species A. lacrimulifera as a separate, valid taxon, based mainly on the granules with a narrow ridge pointing roughly towards the apex of the intermediate valves.

Comparisons. Acanthochitona crinita ( Pennant, 1777) View in CoL is superficially similar to A. andegavensis View in CoL Dell’Angelo, Landau, Van Dingenen & Ceulemans, 2018, from which it differs by the smooth jugal area and the different shape of intermediate and tail valves (see above). Acanthochitona crinita View in CoL also resembles A. pilosa Schmidt-Petersen, Schwabe & Haszprunar, 2015 View in CoL , a Recent species known from the Mediterranean Sea (Renda et al. 2020; Dell’Angelo et al. 2024). The latter differs from A. crinita View in CoL by the shape of the valves (intermediate valves with triangular shaped posterior end and no pronounced apex in A. pilosa View in CoL , posterior margin concave at both sides of the pronounced apex in A. crinita View in CoL ), more oval and densely packed granules, and different dorsal straight spicules on the girdle.

Distribution. Lower Miocene: northeastern Atlantic (Aquitanian-Burdigalian):Aquitaine Basin, France: Coupe du fossé près de La Solitude, Gamachot, Lariey, Maureilhan, Petit Bargues; Proto-Mediterranean Sea (Burdigalian): N. Italy: Sciolze, Valle Ceppi ( Dell’Angelo et al. 2016); Middle Miocene: northeastern Atlantic (Serravallian): Aquitaine Basin, France: Orthez, Sallespisse Carré ( Dell’Angelo et al. 2020b); Proto-Mediterranean Sea (Langhian): Po Basin, N. Italy: Albugnano ( Dell’Angelo et al. 2016); Central Paratethys (Langhian-Serravallian): Austria: Steinabrunn ( Šulc 1934); Hungary: Devecser, Letkés ( Dulai 2025 a, 2025b); Poland: Korytnica, Rybnica ( Bałuk, 1971, 1984; Studencka & Studencki 1988); Upper Miocene: Proto-Mediterranean Sea (Tortonian-Messinian): Po Basin, N. Italy: Borelli, Montegibbio, Rio di Bocca d’Asino (Dell’Angelo et al. 1999, 2016). Lower Pliocene: central Mediterranean, Italy: Liguria: many localities ( Sosso & Dell’Angelo 2010; Dell’Angelo et al. 2013). Pliocene: northeastern Atlantic, Mondego Basin, Portugal ( Dell’Angelo & Silva 2022); western Mediterranean, Estepona Basin, Spain (Dell’Angelo et al. 2004); central Mediterranean, Italy: many localities in Piedmont, Emilia-Romagna, Tuscany, Latium, Sicily ( Dell’Angelo et al. 2001a, 2013; Chirli 2004; Sosso & Dell’Angelo 2010; this study). Upper Pliocene to upper Pleistocene: central Mediterranean, Greece ( Koskeridou et al. 2009). Pleistocene: North Europe: Netherlands ( Strack 2010); northeastern Atlantic: Portugal ( Nobre 1892); central Mediterranean: Italy: many localities in Emilia-Romagna, Tuscany, Puglia, Calabria, Sicily ( Dell’Angelo & Forli 1995a; Dell’Angelo & Giusti 2000; Dell’Angelo et al. 2001a; this study). Recent: Atlantic coast of Europe, from Scandinavia, N. Norway to 67.5° N ( Hansson 1998), all the European coast (McKay & Smith 1979) to Spain and Portugal ( Consolado Macedo & Borges 1999; Urgorri et al. 2017), Berlengas Arch. ( Pisani Burnay 1986), plus Madeira ( Kaas 1991), the Canary Islands ( Kaas 1991; Hernández & Rolán 2011), and the Cape Verde Archipelago ( Kaas 1991; Segers et al. 2009). Mediterranean Sea: Spain ( Salas & Luque 1986), France, Italy ( Dell’Angelo & Smriglio 1999); Croatia ( Dell’Angelo & Zavodnik 2004); Greece and Aegean Sea Islands ( Kattoulas et al. 1973; Strack 1988, 1990; Koukouras & Karachle 2005); Turkey ( Ozturk et al. 2014); Israel ( Barash & Danin 1977); Lebanon ( Crocetta et al. 2014); Tunisia: Gulf of Gabes ( Cecalupo et al. 2008); Black Sea ( Mitov 2015).