Craspedochiton altavillensis (Seguenza, 1876)

Craspedochiton altavillensis (Seguenza, 1876) View in CoL

Fig. 142 View FIGURE 142

Chiton squamosus Libassi, 1859 View in CoL (non Chiton squamosus Linnaeus, 1764 View in CoL , a Recent species from West Indies), p. 14 ( fide Dell’Angelo & Palazzi 1988).

? Chiton sp. Seguenza, 1862a, p. 11 ( fide Dell’Angelo & Palazzi 1988).

Chiton altavillensis Seguenza, 1876, p. 264 ; Seguenza 1879, p. 274; Van Belle 1981, p. 19; Di Geronimo 1991, p. 145.

Craspedochiton altavillensis View in CoL ; Dell’Angelo & Palazzi 1988, p. 174, fig. 1; Dell’Angelo & Forli 1995b, p. 78; Garilli 1998, p. 473; Giani 1998, p. 116; Dell’Angelo et al. 1999, p. 276, 282, pl. 6, figs 1, 2, 5; Dell’Angelo et al. 2001a, p. 153, fig. 31; Dell’Angelo et al. 2003, p. 1193, figs 1–1, 1–2; Forli et al. 2003, p. 152; Chirli 2004, p. 17, pl. 6, fig. 18; Dell’Angelo et al. 2004, p. 40, pl. 2, figs 4, 7; Garilli et al. 2005, p. 140, pl. 5, figs 4–10; Puchalski et al. 2008 (database: chiton fossil records); Sosso & Dell’Angelo 2010, p. 15, unnumbered fig. p. 17; Dell’Angelo et al. 2011, p. 949; Garilli 2011, p. 106, 108; Dell’Angelo et al. 2012, p. 64, figs 6D–H; Dell’Angelo et al. 2013, p. 97, pl. 10, figs R–W; Dell’Angelo et al. 2016, p. 89, pl. 6, figs 5–11; Brunetti & Cresti 2018, p. 28, fig. 11; Dell’Angelo et al. 2020b, p. 43, fig. 28; Dell’Angelo et al. 2021b, p. 429, figs 166–173; Forli & Guerrini 2022, p. 172, fig. 11.10; Brunetti & Cresti 2023, p. 10; Schwabe & Dulai 2024, p. 61, figs 11–14.

Chiton View in CoL ( Acanthochites View in CoL ?) pliocaenicus Brugnone MS, Tiberi, 1877, p. 159 ( fide Dell’Angelo et al. 2012: 65).

Acanthochiton costatus ? var. astensis Sacco, 1897, p. 91 , pl. 7, figs 39–47; Malatesta 1962, p. 167; Van Belle 1981, p. 22; Ferrero Mortara et al. 1984, p. 300; Dell’Angelo et al. 1999, p. 284; Dell’Angelo et al. 2016, p. 91 ( fide Laghi 1977). Gymnoplax deslongchampsi de Rochebrune, 1882, p. 69 , pl. 3, fig. 6; Van Belle 1981, p. 34 ( fide Dell’Angelo & Palazzi 1988).

Craspedochiton deslongchampsi ; Laghi 1977, p. 112, pl. 4, figs 4–8; Sabelli & Taviani 1979, p. 161, pl. 1, fig. 16; Zanaroli 1985, p. 114, pl. 3, figs 5–7; Kroh 2002, p. 10; Dell’Angelo et al. 2016, p. 90.

Acanthochites profascicularis Boettger, 1907, p. 208 ; Van Belle 1981, p. 58; Dell’Angelo et al. 1999, p. 284.

Cryptoconchus ( Craspedochiton) profascicularis ; Šulc 1934, p. 13; Zilch 1934, p. 199, pl. 1, fig. 17.

Cryptoconcha ( Craspedoplax) profascicularis ; Sieber 1956, p. 238.

Cryptoconchus ( Craspedoplax) profascicularis ; Sieber 1959, p. 275; Rado 1969, p. 193, pl. 2, fig. 39; Laghi 1977, p. 112; Dell’Angelo et al., 1999 p. 276; Dell’Angelo et al. 2004, p. 40; Garilli et al. 2005, p. 140.

Acanthochiton View in CoL ( A.) profascicularis ; Stancu & Andreescu 1968, p. 459.

Craspedochiton profascicularis ; Bałuk 1984, p. 292, pl. 12, figs 1–2; Studencka & Studencki 1988, p. 43; Dulai & Studencka 2007, p. 17; Studencka & Dulai 2010, p. 270; Dell’Angelo et al. 2013, p. 98; Dell’Angelo et al. 2016, p. 90, 98; Dell’Angelo et al. 2018b, p. 52, tab. 17; Dell’Angelo et al. 2020b, p. 44.

non Craspedochiton profascicularis ; Studencka & Dulai 2010, text-figs 6C–D (a juv. of an undetermined Craspedochiton View in CoL ).

Craspedochiton schafferi [non Craspedochiton schafferi ( Šulc, 1934) ]; Bałuk 1971, p. 465, pl. 4, figs 13–14 [= Craspedochiton profascicularis (Boettger, 1907) , fide Bałuk 1984].

Cryptoconchus ( Craspedoplax) sp. I Šulc, 1934, p. 13, pl. 1, figs 20–21; Laghi 1977, p. 112; Van Belle 1981, p. 72; Dell’Angelo et al. 1999, p. 276, 284; Studencka & Dulai 2010, p. 270.

Type material. Neotype MZB 7062 (head valve), designated by Dell’Angelo & Palazzi (1989: fig. 1).

Type locality. Altavilla Milicia ( Sicily, Italy) .

Type stage. Pliocene-Pleistocene (upper Piacenzian to lower Gelasian) ( Dominici et al. 2020).

Material examined. Lower Miocene ( Burdigalian): France: Carrière Vives: 10 valves ( BD 1113, MZB 50584– 50585), Pont St Martin: 1 valve ( JFL); Italy: Valle Ceppi: 3 valves ( MZB 32115–32116, PG). Middle Miocene: Central Paratethys: Austria: Forchtenau: 2 valves ( NHMV 1866/0001/1209, as Cryptoconchus ( Craspedochiton) profascicularis , Figs 143M–O View FIGURE 143 ); Hungary: Letkés: 1 valve ( BD 1114). Upper Miocene (Tortonian): Italy: Borelli: 8 valves ( BD 1115, MZB 32119–32120, Fig. 142C View FIGURE 142 , MGPT, PG), Montegibbio: 2 valves ( LB), Rio di Bocca d’Asino: 8 valves ( BD 1116, MZB 32117–32118, PG). Lower Pliocene (Zanclean): Italy: Borzoli: 66 valves ( BD 1117, Figs 142H–I View FIGURE 142 , MZB 45773), Caranchi: l valve ( MP), Garlenda: 3 valves ( MP), Rio Sant’ Antonino: 47 valves ( BD 1118, MP, MZB 45772, PG), Rio Torsero: 2 valves ( BD 1119, PG), Zinola: 1 valve ( MZB 45771). Pliocene: Spain: Estepona: 17 valves ( BD 1120); Italy: Piedmont: Valle Andona: 5 valves ( BD 1121, NHMV 1877A/0018/0088, the tail valve described and figured by Šulc, as Cryptoconchus ( Craspedoplax) sp. I, Fig. 143P View FIGURE 143 ), Valle Botto: 1 valve ( BD 1122); Tuscany: Bibbiano: 1 valve ( BD 1123), Castell’Anselmo: 1 valve ( BD 1124), Cigliano: 1 articulated spm ( MZUB); Luciana: 2 valves ( BD 1125), Orciano Pisano: 6 valves ( BD 1126), Pietrafitta Melograni: 1 valve ( BD 1127), Serre di Rapolano: 6 valves ( BD 1128), Volterra: 1 valve ( BD 1129); Emilia-Romagna: Bacedasco: 1 valve ( BD 1130), Cava di Campore: 5 valves ( BD 1131); Umbria: Cava di Ficulle: 1 valve ( BD 1132), Monteleone d’Orvieto: 2 valves ( BD 1133); Latium: Magliano Sabina: 2 valves ( BD 1134); Sicily: Altavilla: 100 valves ( AG, AR, BD 1135, Figs 142D, 142J–L View FIGURE 142 ); Sicily: Trappeto: 3 valves ( BD 1136). Pleistocene: Italy: Sicily: Dattilo: 1 valve ( BD 1137, Figs 142E–G View FIGURE 142 ); Greece: Kyllini: 5 valves ( BD 1138, DGUP, Figs 142A–B View FIGURE 142 ). Maximum width of the valves: 9.8 / 27 / 8.6 mm.

Description. Head valve semicircular, with five well evident radial ribs, slope almost straight. Intermediate valve polygonal (WT/LT = 1.78–2.75), semicarinate in anterior profile, moderately elevated (H/W = 0.23–0.42), anterior margin almost straight in jugum, side margins straight, posterior margin straight or slightly concave at both sides of prominent apex, jugal area large, triangular, lateral areas well separated from central area by a large diagonal fold. Tail valve elliptical (WT/LT = 1.62–1.89), anterior margin straight or slightly concave between apophyses, mucro subcentral, not elevated and poorly developed, antemucronal slope straight or slightly convex, postmucronal slope concave just behind mucro.

Tegmentum covered with large, elevated granules of irregular shape, except on JA; shape, elevation and density of granules and granulation patterns highly variable, from single granules, regularly ellipsoidal, to coalescent granules forming irregular cords, JA smooth, top of granules convex. Each granule with many megalaesthetes and micraesthetes (up to 20–25 or more) arranged without any apparent order.

Articulamentum with trapezoidal, large apophyses, expanded in tail valve, large posterior callus in tail valve, slit formula 5 / 1 / 7–8, insertion lamina reduced to a rather narrow band in head valve, teeth broad, roughed dorsally, more irregular in tail valves, slits deep, dorsally slightly elevated, forming channel.

Remarks. Craspedochiton altavillensis (Seguenza, 1876) is characterized by a tegmentum covered with large, elevated granules of irregular shape, except on JA (smooth). The synonymy of Craspedochiton deslongchampsi (de Rochebrune, 1882) with C. altavillensis was established and discussed by Dell’Angelo & Palazzi (1988).

Dell’Angelo et al. (2003) reported a complete, articulated specimen of Craspedochiton altavillensis from the Italian Pliocene, the only case known to date.

Chiton View in CoL ( Acanthochites View in CoL ?) pliocaenicus Brugnone MS, Tiberi, 1877 was described from Altavilla. The original description is somewhat difficult to be interpreted and contains a mention to Chiton squamosus Libassi, 1859 View in CoL (non Linnaeus, 1764), which is a synonym of Chiton altavillensis ( Dell’Angelo & Palazzi, 1988). The location of the type material is unknown, and Tiberi’s species is tentatively kept as a synonym of Craspedochiton altavillensis View in CoL , as already suggested by Dell’Angelo et al. (2012).

Boettger (1907) described the new species Acanthochites profascicularis on a single head valve found at Coştei ( Romania, Middle Miocene). Boettger did not figure this valve, which was later illustrated by Zilch (1934: 199, pl. 1, fig. 17). Šulc and Zilch were of the opinion that Cryptoconchus ( Craspedochiton) profascicularis was conspecific with Acanthochiton costatus Sacco, 1897 , and that the taxon to be used was profascicularis , as the Sacco’s name is preoccupied by Acanthochites costatus View in CoL H. & A. Adams, 1864. Laghi (1977) revised the material of Sacco from Piedmont, and considered costatus View in CoL ( = profascicularis ) a valid species, while Dell’Angelo et al. (1999) considered costatus View in CoL conspecific with Craspedochiton altavillensis (Seguenza, 1876) View in CoL . Studencka & Dulai (2010) summarize the different interpretations given to these taxa, considering also that the original material of A. costatus View in CoL refer to two different species of Craspedochiton View in CoL , C. costatus View in CoL (the specimens from Turin hills, and those from the Tortonian of Montegibbo reported by Sacco as Acanthochiton costatus var. mutinocrassa , that we consider in this study as Craspedochiton mutinocrassus , see below) and C. altavillensis View in CoL (the specimens from the Pliocene of Italy reported by Sacco as Acanthochiton costatus ? var. astensis ).

Two valves (head and intermediate) from Forchtenau are present in the Šulc collection at NHMW. The head valve ( Fig. 142M View FIGURE 142 ) is identical to the holotype of Boettger figured by Zilch, and to the neotype of Craspedochiton altavillensis designated by Dell’Angelo & Palazzi (1988). The comparison of these two valves enabled Dell’Angelo et al. (1999, 2016) to consider Cryptoconchus ( Craspedochiton) profascicularis conspecific with Craspedochiton altavillensis , and we confirm this synonymy. The incomplete intermediate valve ( Figs 142N–O View FIGURE 142 ) is consistent with the attribution to C. altavillensis , by its pentagonal layout, the raised rib separating the lateral and lateropleural areas, the tegmentum covered with large, elevated granules of irregular shape, except for JA.

The tail valve figured by Šulc (1934: pl. 1, figs 20–21) as Cryptoconchus ( Craspedoplax) sp. I, from the Pliocene of Valle Andona ( Italy), is present in the Šulc collection at NHMW ( Fig. 142P View FIGURE 142 ). We agree that this valve is within the range of variability of Craspedochiton altavillensis , as already reported by Laghi (1977) and Dell’Angelo et al. (1999).

Dell’Angelo et al. (2016) reported Craspedochiton altavillensis from the lower Miocene (Burdigalian) of the Turin Hills, Piedmont up to the Pleistocene of Greece and Italy. Such an extended stratigraphic range with different paleoclimatic scenarios and paleobiogeographic distribution is suspect, and may suggest that it may be a group of morphologically closely-related species. Dell’Angelo et al. (2016) have provisionally adopted a conservative approach and used the species name in a broad sense, pending further study.

Comparisons. The species of Craspedochiton with the closest sculpture to C. altavillensis (large irregular granules tending to coalesce)is C. lozoueti Dell’Angelo, Lesport, Cluzaud & Sosso, 2020, which however differs from C. altavillensis (Seguenza, 1876) mainly for the greater elevation of the valves (more flattened in C. altavillensis ), LA not separated from CA (well separated by a large diagonal fold in C. altavillensis ), and the different shape of the tail valve. See Tab. 23 for a comparison with the Craspedochiton spp . considered in the present study.

Distribution. Lower Miocene: northeastern Atlantic (Burdigalian): Aquitaine Basin, France: Carrière Vives, Pont St Martin ( Dell’Angelo et al. 2020b); Proto-Mediterranean Sea (Burdigalian): N. Italy: Valle Ceppi ( Dell’Angelo et al. 2016); Middle Miocene: Central Paratethys (Langhian-Serravallian): Austria: Forchtenau ( Šulc, 1934), Poland: Korytnica ( Bałuk 1971, 1984), Hungary: Borsodbóta, Letkés ( Schwabe & Dulai 2024; this study), Romania: Costej (Boettger 1907; Zilch 1934; Dell’Angelo et al. 1999); Eastern Paratehys: Ukraine: Varovtsi ( Studencka & Dulai 2010); Upper Miocene: Proto-Mediterranean Sea (Tortonian): N. Italy: Borelli, Montegibbio, Rio di Bocca d’Asino ( 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: Estepona (Dell’Angelo et al. 2004); central Mediterranean, Italy: many localities in Piedmont, Emilia-Romagna, Tuscany, Umbria, Latium, Sicily ( Dell’Angelo et al. 2001a, 2012, 2013; Chirli 2004; Sosso & Dell’Angelo 2010; this study). Pleistocene: central Mediterranean, S. Italy: Dattilo ( Garilli 1998, 2011; this study), Greece: Kyllini ( Garilli et al. 2005).