Acanthochitona fascicularis ( Linnaeus, 1767 )

Acanthochitona fascicularis ( Linnaeus, 1767) View in CoL

Fig. 136 View FIGURE 136

Chiton fascicularis Linnaeus, 1767, p. 1106 ; Philippi 1844, p. 83; Bronn 1848, p. 292; Baily, 1859, p. 334; Baily, 1860, p. 171; Unger & Kotschy 1865, p. 43; Appelius 1871, p. 202, 225, 252, 264; Tiberi 1877, p. 136; Ulzega 1980, p. 56.

Acanthochites fascicularis View in CoL ; Seguenza 1879, p. 357; de Rochebrune 1883, p. 71.

Acanthochitona fascicularis View in CoL ; Fischer & Renner 1979, p. 49, figs 2, 4–6, 11, 15; Kaas 1985a, p. 585, figs 1–6; Brambilla & Lualdi 1988, p. 19; Dell’Angelo & Forli 1995a, p. 235, figs 8, 11; Dell’Angelo & Giusti 1997, p. 55, figs 14, 16; Garilli 1998, p. 473; Giani 1998, p. 116, pl. 43, fig. 7; Mancini 1998, p. 30, pl. 1, unnumbered figs; Buccheri et al. 1999, p. 366; Dell’Angelo & Smriglio 1999, p. 192, pls 64–65, figs 113–123; Dell’Angelo et al. 1999, p. 273, pl. 5, figs 1, 3–5, pl. 5, figs 3, 4, 6; Forli et al.1999, p. 113, pl. 1, fig. 10; Mancini 1999, p. 20; Dell’Angelo et al. 2001a, p. 153, figs 30, 33; Forli et al. 2003, p. 152; Chirli 2004, p. 16, pl. 6, figs 9-17; Dell’Angelo et al. 2004, p. 40, pl. 3, fig. 8, pl. 4, fig. 1; Garilli et al. 2005, p. 139, pl. 5, figs 1–3; Dell’Angelo & Vardala-Theodorou 2006, p. 331, 1 unnumbered fig.; Dell’Angelo et al. 2007b, p. 141; Vardala-Theodorou & Nicolaidou 2007, p. 64; Puchalski et al. 2008 (database: chiton fossil records); Koskeridou et al. 2009, p. 322, figs 11.3–11.8; Sosso & Dell’Angelo 2010, p. 15, unnumbered fig. p. 17; Strack 2010, p. 65, figs 60–61; Bonfitto et al. 2011, p. 173, figs 1, 4A, 5, 6A; Dell’Angelo et al. 2012, p. 63, figs 6A–B; Dell’Angelo et al. 2013, p. 95, pl. 10, figs A–G; Moissette et al. 2013, p. 17; Ciampalini et al. 2014, p. 13; Schmidt-Petersen et al. 2015, p. 18, fig. 6, tab. 1; Dell’Angelo et al. 2016, p. 86, pl. 5, figs 1–11 [ non fig. 3 (= A. andegavensis View in CoL ) and fig. 9 (= A. mathiasi sp. nov.)]; Brunetti & Cresti 2018, p. 28, fig. 10; Dell’Angelo et al. 2018b, p. 41, tab. 14, 17; Dell’Angelo et al. 2020b, p. 38, fig. 24; Dell’Angelo et al. 2021b, p. 427, figs 150–157; Brunetti & Cresti 2023, p. 10.

non Chiton fascicularis ; Wood 1842, p. 459; Morris 1843, p. 142; Tennant 1847, p. 17; Wood 1848, p. 185, pl. 20, fig. 9a–9b; Morris 1854, p. 243; Reid 1890, p. 261, tab. 3 (reports from the English Pliocene not attributable at specific level, see Section “Species of unclear taxonomic position, Chiton woodi de Rochebrune, 1882 ”).

non Chiton ( Acanthochites) fascicularis var.; Reuss 1860, p. 260, pl. 8, figs 4–6 [= A. faluniensis (de Rochebrune, 1882) ].

non Chiton fascicularis var.; Procházka 1895, p. 99; Procházka 1900, p. 117 [= A. faluniensis (de Rochebrune, 1882) ].

non Acanthochitona fascicularis View in CoL ; Bałuk 1984, p. 291, pl. 9, fig. 2 [= A. crinita ( Pennant, 1777) View in CoL ].

non Acanthochitona fascicularis View in CoL ); Vetters 1910, p. 157; Dell’Angelo et al. 2007a, p. 44, fig. 4e [= A. faluniensis (de Rochebrune, 1882) ].

non Acanthochiton aff. fascicularis View in CoL ; Sieber 1958, p. 144; Sieber 1959, p. 275 [= A. faluniensis (de Rochebrune, 1882) ].

Chiton discrepans [non Acanthochitona discrepans ( Brown, 1827) View in CoL ]; Monterosato 1872, p. 28; Seguenza 1874, p. 12; Seguenza 1876, p. 264; Brugnone 1877, p. 18; Tiberi 1877, p. 137, 146, 153; Coppi 1880, p. 227.

Chiton ( Acanthochites) discrepans [non Acanthochitona discrepans ( Brown, 1827) View in CoL ]; Monterosato 1877, p. 33; Brugnone 1880, p. 132

Acanthochites discrepans View in CoL [non Acanthochitona discrepans ( Brown, 1827) View in CoL ]; Monterosato 1879, p. 29; Seguenza 1879, p. 321; Coppi 1881, p. 87.

Anisochiton discrepans View in CoL [non Acanthochitona discrepans ( Brown, 1827) View in CoL ]; B.D.D. 1882, p. 508; Castany et al. 1956, p. 49; Blanc et al. 1953, p. 15.

Acanthochiton discrepans View in CoL [non Acanthochitona discrepans ( Brown, 1827) View in CoL ]; Scalia 1900, p. 16; Crema 1903, p. 255; Scalia 1907, p. 29; Francaviglia 1940, p. 65.

Acanthochites communis Risso, 1826, p. 268 View in CoL .

Acanthochiton communis View in CoL ; Leloup & Volz 1938, p. 57; Caldara 1986, p. 136.

Acanthochitona communis View in CoL ; Leloup 1941, p. 1, figs 1–3, pl. 1, fig. 1; Malatesta 1962, p. 166, figs 24–25; Compagnoni & Conato 1969, p. 45, pl. 3, fig, 2; Ricchetti & D’Alessandro 1972, p. 133; Ruggieri & Milone 1973, p. 221; Laghi 1977, p. 110, pl. 3, figs 13–19; Ruggieri & Unti 1978, p. 50; Sabelli & Taviani 1979, p. 161, pl. 1, figs 13–14; Giammarinaro & Gucciardo 1981, p. 38; Porta & Martinell 1981, p. 15; Laghi 1984, p. 556; Zanaroli 1985, tab. 2; Tabanelli & Segurini 1994, p. 7; Bellomo & Sabelli 1995, p. 201.

non Acanthochitona communis View in CoL ; Jakubowski & Musiał 1979, p. 51, pl. 2, fig. 3.

Craspedochiton ( Pseudoacanthochitona) ambiguus Laghi, 1977, p. 112 , pl. 4, figs 13–16; Van Belle 1981, p. 20; Bałuk 1984, p. 292; Zanaroli 1985, tab. 2; Dell’Angelo et al. 2013, p. 96 ( fide Dell’Angelo et al. 1999: 285).

Craspedochiton ambiguus ; Dell’Angelo et al. 1999, p. 285.

Type material. MNHN, Neotype designated and figured by Kaas (1985a: p. 588, fig. 1).

Type locality. “ in Barbaria”; Neotype: Oran, Algeria.

Material examined. Lower Miocene: France (Aquitanian): Lariey; 1 valve ( JFL); France ( Burdigalian): Carrière Vives: 1 valve ( BD 1022), Gamachot: 3 valves ( AC, BD 1023, MZB 50578, Figs 136A–B View FIGURE 136 ), Le Thil: 1 valve ( PR), Maureilhan: 4 valves ( BD 1024); Italy (Burdigalian): Valle Ceppi: 2 valves ( BD 1025). Middle Miocene: France (Serravallian): Carré: 1 valve ( MZB 50579, Figs 136C–D View FIGURE 136 ). Upper Miocene: France (Messinian?): Moulin-Pochas: 6 valves ( PR); Italy (Tortonian): Borelli: 17 valves ( BD 1026, MGPT, MZB 32106, PG), Montegibbio: 94 valves ( BD 1027), Rio di Bocca d’Asino: 396 valves ( BD 1028, MZB 32100–32105, Figs 136I–L View FIGURE 136 , PG), S. Agata Fossili: 10 valves ( PG), Vigoleno: 2 valves ( BD 1029), Villa Monti: 32 valves ( BD 1030, PG). Lower Pliocene: Italy: Liguria: Borzoli: 366 valves ( BD 1031), Bussana: 114 valves ( BD 1032), Caranchi: 42 valves ( BD 1033), Garlenda: 10 valves ( MP), Genova Sestri: 5 valves ( BD 1034), Rio Sant’ Antonino: 427 valves ( BD 1035, Figs 136E–F View FIGURE 136 , MP, MZB 45761–45765), Rio Torsero: 36 valves ( BD 1036, MP, PG, SR), Salea: 1 valve ( BD 1037), Zinola: 2 valves ( BD 1038). Pliocene: Spain: Barcelona, El Papiol: 2 valves ( BD 1039), Estepona: 40 valves ( BD 1040); Italy: Piedmont: San Damiano: 2 valves ( VB), Vintebbio: 13 valves ( BD 1041); Tuscany: Bibbiano: 11 valves ( BD 1042), Castell’Anselmo: 3 valves ( BD 1043), Castiglioncello del Trinoro: 7 valves ( BD 1044), Cetona: 1 valve ( BD 1045), Colle Val d’Elsa: 1 valve ( BD 1046), Monte Antico: 1 valve ( BD 1047), Montenero: 3 valves ( BD 1048), Orciano Pisano: 75 valves ( BD 1049), Pietrafitta: 62 valves ( BD 1050), Pietrafitta Melograni: 32 valves ( BD 1051), Pontedera: 2 valves ( BD 1052), San Miniato: 9 valves ( BD 1053), Serre di Rapolano: 8 valves ( BD 1054); Emilia-Romagna: Castell’Arquato: 1 valve ( BD 1055), Cava di Campore: 19 valves ( BD 1056), Gagliardella: 6 valves ( BD 1057); Umbria: Orvieto: 2 valves ( BD 1058); Latium: Magliano Sabina: 1 valve ( BD 1059), Monte Mario: 2 valves ( BD 1060), Montelibretti: 1 valve ( BD 1061); Sicily: Altavilla: 27 valves ( AG, AR, BD 1062), Sciacca: 4 valves ( BD 1063), Trappeto: 3 valves ( BD 1064). Pleistocene: Italy: Tuscany: Caletta: 3 valves ( BD 1065), Capraia Island-Capo Corso: 157 valves ( BD 1066), Cisternino: 48 valves ( BD 1067), Fauglia: 48 valves ( BD 1068), Riparbella: 29 valves ( BD 1069); Emilia-Romagna: Torrente Arda: 2 valves ( BD 1070), Torrente Stirone: 12 valves ( BD 1071); Puglia: Cutrofiano: 2 valves ( BD 1072), Gallipoli: 4 valves ( BD 1073), Marina di Novaglie : 2 valves ( BD 1074), Porto Pirrone: 3 valves ( BD 1075); Calabria: Archi S. Francesco: 81 valves ( BD 1076), Bovetto: 1 valve ( BD 1077), Carrabbati: 33 valves ( BD 1078), Castellace: 2 valves ( BD 1079), Gallina: 7 valves ( BD 1080), Le Castella: 76 valves ( BD 1081), Monasterace: 6 valves ( BD 1082), Musalà: 4 valves ( BD 1083), Pecoraro: 14 valves ( BD 1084), Petti di Carrubbare: 20 valves ( BD 1085), Pezzo: 234 valves ( BD 1086), S. Maria di Catanzaro: 2 valves ( BD 1087), San Procopio: 6 valves ( BD 1088), Saracinello: 1 valve ( BD 1089), Stalettì: 6 valves ( BD 1090), Terreti: 24 valves ( BD 1091), Torrente Boscaino: 3 valves ( BD 1092), Vito Superiore: 1 valve ( BD 1093); Sicily: Calderà: 2 valves ( BD 1094), Capo Milazzo: 15 valves ( BD 1095), Dattilo: 3 valves ( BD 1096), Grammichele: 1 valve ( BD 1097), Melilli: 1 valve ( BD 1098), Menfi: 9 valves ( BD 1099), Messina : 2 valves ( BD 1100), Ogliastro: 2 valves ( BD 1101), Salice: 2 valves ( BD 1102), Selinunte Casa Catarinicchia: 3 valves ( BD 1103), Selinunte Casa Parrino: 10 valves ( BD 1104), Vittoria Case Buffa: 1 valve ( BD 1105). Greece: Kyllini: 58 valves ( BD 1106, DGUP, Figs 136G–H View FIGURE 136 ), Perachora: 31 valves ( BD 1107), Rhodes: Kritika: 6 valves ( BD 1108). Maximum width of the valves: 5.3 / 8 / 7.5 mm.

Description. Head valve semicircular, posterior margin straight, apex scarcely evident. Intermediate valves broadly rectangular (WT/LT = 1.60–2.10), moderately elevated (H/W = 0.37–0.48), semicarinate in anterior profile, posterior margin slightly concave on both sides of pronounced apex, jugal area generally narrow, longitudinally striated, raised, neatly separated from lateropleural area. Tail valve broadly circular, just straighter in jugal area (WT/LT = 1.20–1.29), jugal area longitudinally striated, raised, neatly separated from lateropleural area, mucro well evident in central position, antemucronal slope slightly convex, postmucronal slope strongly concave behind the mucro.

Whole tegmentum (except JA) sculptured with densely packed roundish to oval granules, rather elevated, arranged along arched lines, with flat or slightly concave surface, sometimes with a characteristic incision in the middle of the granule posterior margin, JA longitudinally striated; granules small, widely separated from each other, of variable size, maximum diameter 93 μm, with a single central megalaesthete generally surrounded by 1 to 5 irregularly arranged micraesthetes (sometimes 0).

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

Remarks. Acanthochitona fascicularis ( Linnaeus, 1767) is an extremely variable species with a complicated synonymy. Kaas (1985a) gives an accurate analysis of the taxonomic history of the three European species of Acanthochitona considered valid at the time, i.e. A. fascicularis , A. crinita ( Pennant, 1777) and A. discrepans ( Brown, 1827) , Only Acanthochitona fascicularis and A. crinita occur in the Mediterranean Sea, while A. discrepans is known from northeastern Ireland and England.

Before the work of Kaas (1985a), Acanthochitona fascicularis was reported in the literature mainly as A. communis Risso, 1826 , or A. discrepans (non Brown, 1827), while A. crinita was reported mainly as A. fascicularis (non Linnaeus, 1767).

All Mediterranean fossil records of A. discrepans are here attributed to A. fascicularis ; reports of A. discrepans from the English Pliocene (Coralline Crag, Sutton), could be related to the true A. discrepans .

Laghi (1977) described the new species Craspedochiton ( Pseudoacanthochitona) ambiguus upon valves from the lower Pliocene of “La Tagliata”, a locality near Modena. This species differs from A. fascicularis by the elliptical section granules (vs. those more rounded of A. fascicularis ) and mainly by the tail valve with numerous slits (vs. 2 slits of A. fascicularis ). Bałuk (1984) and Dell’Angelo et al. (1999) have already observed that the greatest number of slits in the tail valve may fall in the intraspecific variability of A. fascicularis , and therefore we agree with these authors in considering Craspedochiton ambiguus a junior synonym of A. fascicularis . Several tail valves with more than two slits have already been reported in the literature (e.g., Dell’Angelo et al. 2013: pl. 10, figs F–G; Dell’Angelo et al. 2016: pl. 5, figs 6–7, and this study: Figs 136J–L View FIGURE 136 ).

The great variability of the valves has been widely discussed (e.g., Leloup 1941, 1969; Dell’Angelo & Smriglio 1999; Dell’Angelo et al. 2013, 2016, 2020b). Also, the shape of granules is variable, sometimes the surface shows a characteristic incision on the surface, as well figured by Fisher & Renner (1979: figs 4–6), Bonfitto et al. (2011: fig. 1) and Vončina et al. (2023: figs 4C, 8B) on living specimens. In the fossil material examined, are both valves with granules without ( Fig. 136F View FIGURE 136 ) and with incisions ( Fig. 136H View FIGURE 136 ), sometimes not as evident as those depicted for living specimens.

Comparisons. Acanthochitona fascicularis is closest to A. faluniensis (de Rochebrune, 1882) , from which it is practically indistinguishable (see above).

Distribution. Lower Miocene: northeastern Atlantic (Aquitanian-Burdigalian): Aquitaine Basin, France: Carrière Vives, Gamachot, Lariey, Le Thil, Maureilhan ( Dell’Angelo et al. 2020b); Proto-Mediterranean Sea (Burdigalian): N. Italy:Valle Ceppi ( Dell’Angelo et al. 2016); Middle Miocene: northeastern Atlantic (Serravallian): Aquitaine Basin, France: Sallespisse ( Dell’Angelo et al. 2020b); Upper Miocene: northeastern Atlantic: Ligerian Basin, France: Moulin Pochas ( Dell’Angelo et al. 2020b); Proto-Mediterranean Sea (Tortonian): Po Basin, N. Italy: Borelli, Montegibbio, Rio di Bocca d’Asino, S. Agata Fossili, Vigoleno, Villa Monti ( Laghi 1977; Dell’Angelo et al. 1999, 2016). Lower Pliocene: central Mediterranean, Italy: Liguria: many localities ( Sosso & Dell’Angelo 2010; Dell’Angelo et al. 2013, 2021b). Pliocene: western Mediterranean, Estepona Basin, Spain ( Mancini 1998; Dell’Angelo et al. 2004, 2012); central Mediterranean, Italy: many localities in Piedmont, Emilia-Romagna, Sicily, Umbria, Latium, Sicily ( Malatesta 1962; Laghi 1977; Dell’Angelo et al. 2001a; Chirli 2004; this study). Upper Pliocene to upper Pleistocene: central Mediterranean, Greece ( Koskeridou et al. 2009). Pleistocene: North Atlantic: Netherlands ( Strack 2010); central Mediterranean, Italy: many localities in Emilia-Romagna, Tuscany, Puglia, Calabria, Sicily ( Malatesta 1962; Dell’Angelo & Forli 1995a; Dell’Angelo et al. 2001a; this study), Greece: Kyllini, Perachora ( Garilli et al. 2005; this study), Tunisia: Monastir ( Castany et al. 1956). Recent: A tlantic coast of Europe: from the English Channel and Bretagne (McKay & Smith 1979) to Spain and Portugal ( Borja 1987; Rolan Mosquera et al. 1990; Consolado Macedo et al. 1999; Strack 2010; Urgorri et al. 2017), Berlengas Arch. ( Pisani Burnay 1986), plus the Azores ( Kaas 1991; Avila & Sigwart 2013), Madeira ( Kaas 1991) and Selvagens Arch. ( Kaas 1991) and the Canary Islands ( Kaas 1991; Hernández & Rolán 2011). 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 ( Kaas 1989; Cecalupo et al. 2008); Black and Marmara Sea ( Öztürk et al. 2014).