Hanleya hanleyi

Hanleya hanleyi View in CoL (Bean in Thorpe, 1844)

Fig. 43 View FIGURE 43

Chiton hanleyi Bean in Thorpe, 1844, p. 263, fig. 57; Reid 1890, p. 261, tab. 3.

Hanleya hanleyi View in CoL ; Malatesta 1962, p. 153, figs 9–10; Sabelli 1972, p. 97, figs 1–6; Sabelli 1974a, figs 1–13; Laghi 1977, p. 99, figs 5–9; Marquet 1984, p. 336, pl. 1, fig. 3; Kaas & Van Belle 1985a, p. 193, fig. 91, map 18; Zanaroli 1985, p. 75; Dell’Angelo & Giusti 1997, p. 51, fig. 2; Dell’Angelo et al. 1999, p. 262, pl. 1, fig. 1 ( partim); Dell’Angelo & Smriglio 1999, p. 85, pl. 25 figs C–D, G, pl. 26 figs I–J, color figs 34–36 ( partim); Dell’Angelo et al. 2001a, p. 147, fig. 8; Marquet 2002, p. 13, pl. 2, fig. 2; Sirenko 2014, p. 2915, 2030, 2939; Sirenko et al. 2016, p. 58, figs 1–10; Dell’Angelo et al. 2018b, p. 20, fig. 10; Dell’Angelo et al. 2020b, p. 52, tab. 9, Dell’Angelo et al. 2021a, p. 125, fig. 1; Dell’Angelo et al. 2022, p. 6, fig. 4; Taviani et al. 2023: p.9, fig. 5.

non Hanleya hanleyi View in CoL ; Dell’Angelo & Forli 1995a, p. 225; Dell’Angelo et al. 1998a, p. 244, pl. 2, figs 1–2; Dell’Angelo et al. 1999, p. 262, pl. 1, fig. 3; Dell’Angelo & Smriglio 1999, p. 85, pl. 25 figs A–B, E–F, H, pl. 26 figs K, L–P ( partim); Dell’Angelo et al. 2004, p. 30, pl. 2, fig. 8; Dell’Angelo et al. 2012, p. 56, fig. 3F; Dell’Angelo et al. 2013, p. 76, pl. 3, figs D–F (= H. mediterranea View in CoL , fide Sirenko 2014; Dell’Angelo et al. 2015a; this study).

Chiton nagelfar Lovén, 1846, p. 158 .

Hanleya nagelfar View in CoL ; Kaas & Van Belle 1985a, p. 196, fig. 92, map 19; Bellomo & Sabelli 1995, p. 201, text-fig. 1; Puchalski et al. 2008 (database: chiton fossil records); Sirenko 2014, p. 2931 View Cited Treatment , figs 9–19; Dell’Angelo et al. 2015a, p. 231, pl. 4, figs 10–12; Dell’Angelo et al. 2004, p. 30, pl. 2, fig. 8; Dell’Angelo et al. 2016, p. 96; Forli & Guerrini 2022, fig. 11.7.

non Hanleya nagelfar View in CoL ; Dell’Angelo et al. 1998a, p. 244, pl. 1, fig. 10 (= Hanleya barbarae sp. nov., fide this study).

Chiton strigillatus Wood, 1842, p. 459 ; Van Belle 1981, p. 73 ( nomen nudum).

Chiton strigillatus Wood, 1848, p. 186 , pl. 20, fig. 10a–b; Bronn 1848, p. 292; Morris 1854, p. 243; Wood 1872 –1874, p. 95; Woodward H.B. 1881, p. 48; Van Belle 1981, p. 73 (= Hanleya hanleyi View in CoL , fide Wood 1872 –1874).

? (reported as Chiton hanleyi without description or figures); Seguenza 1876, p. 264; Brugnone 1877, p. 18; Tiberi 1877, p. 146, 154; Brøgger 1901, p. 656; Antevs 1928, p. 666–677.

? (reported as Acanthopleura hanleyi without description or figures); Monterosato 1879, p. 27.

? (reported as Hanleya hanleyi without description or figures); Vazzana 1996, p. 148; Long & Zalasiewicz 2011, p. 66, App. 10.

Type material. Syntype, Scarborough Museums Trust , Woodend, Scarborough, U.K. ( Sirenko et al. 2016) .

Type locality. Scarborough ( Yorkshire, England) .

Material examined. Upper Miocene (Tortonian): France: Saint-Clément-de-la-Place: 25 valves ( MNHN. F.A67078, Figs 43B–D View FIGURE 43 ), MNHN.F.A67079, RGM.1008399–1008400, RGM.1008430, BD 136). Italy: Borelli: 1 valve ( MGPT PU 135038), Rio di Bocca d’Asino: 2 valves ( BD 424, MZB 32016). Lower Pliocene: Italy: Liguria: Bussana: 1 valve ( BD 425). Pliocene: Portugal: Vale de Freixo: 2 valves ( RGM.1364001, GeoFCUL VFX.03.364). Upper Pliocene to lower Pleistocene: France: St. Julien-de-Concelles: 1 valve ( RGM.1008441). Pleistocene: Italy: Tuscany: Capraia Island-Capo Corso - 350m: 3 valves ( BD 426); Puglia: SE06-19: 1 valve ( MZUB, Fig. 43E–F View FIGURE 43 ); Calabria: Archi S. Francesco: 7 valves ( BD 427, Figs 43A View FIGURE 43 ), Musalà: 4 valves ( BD 428), Terreti: 1 valve ( BD 429), Vallone Catrica: 1 valve ( BD 430); Sicily: Ficarazzi: 1 valve ( BD 431), Salice: 22 valves ( BD 432, Figs 43G–H View FIGURE 43 ). Maximum width of the valves: 2.3 / 5.5 / 4.1 mm. (15.8 / 19 / 18.9 for extant H. nagelfar , see Sirenko 2014).

Description. Head valve semicircular, posterior margin widely V-shaped, notched in middle. Intermediate valves broadly rectangular (W/L = 1.87–2.10), moderately elevated (H/W = 0.30–0.42), carinate in anterior profile, anterior margin undulating, side margins evenly rounded, posterior margin practically straight, except for protruding, well developed apex in middle, lateral areas not raised, only marked by a difference in sculpture. Tail valve somewhat elliptical (W/L = 1.53–1.72), anterior margin slightly convex between apophyses, central protruding rounded mucro, antemucronal slope slightly convex, postmucronal slope practically straight, only slightly concave just below mucro.

Tegmentum surface slightly rough, space between striae of granules large. HV, LA and PMA uniformly sculptured with numerous, oval granules, randomly disposed, increasing in size and spacing towards outer margins. CA and AMA sculptured with roundish to oval granules (length 75–100 µm), arranged in longitudinal striae, fine and close set on JA, getting larger and posteriorly converging towards side margins. Each granule contains one central megalaesthete surrounded by 8–12 micraesthetes, megalaesthete slightly larger in some cases, but almost same width.

Articulamentum with apophyses rather large, broadly triangular with rounded top, separated by a slightly concave jugal sinus, about ⅓ of valve ‘s width, connected to primordium of insertion plates in intermediate valves, insertion plates weakly developed in head and tail valves.

Remarks. This species has a complex taxonomic history, and many synonyms are known and accepted ( Sirenko et al. 2016). Several publications reported Hanleya hanleyi Bean in Thorpe, 1844 as occurring in the Mediterranean Sea and in deposits from Neogene of Italy ( Sabelli 1972, 1974a; Dell’Angelo & Smriglio 1999; Dell’Angelo et al. 2015a, 2021a). Recently, another species of Hanleya ( H. mediterranea Sirenko, 2014 ) has been described from the Mediterranean Sea ( Dell’Angelo et al. 2021a), and both species occur in fossil deposits from Italy, at places together (e.g., in the Upper Miocene of Borelli, see Dell’Angelo et al. 2015a). Therefore, for some bibliographical references of fossil H. hanleyi (without description and/or figures) a specific determination ( H. hanleyi or H. mediterranea ) cannot be reached. Also, a list of bibliographical references for living Hanleya in the Mediterranean Sea has been given by Dell’Angelo et al. (2021a: 133), under the taxon “ Hanleya sp. indet.”.

The sculpture shows a certain variability, as has been reported by Dell’Angelo et al. (2021a) on recent species, the longitudinal series of granules are more or less regular, some split ( Dell’Angelo et al. 2021a: fig. 1. D) and some converge towards the jugal area ( Figs 43B, 43G View FIGURE 43 ), the interstices can be more or less narrow.

Chiton strigillatus Wood, 1848 is considered a synonym of Hanleya hanleyi View in CoL , as already observed by Wood (1872 –1874). The description and figures given by Wood (1848) agree with the attribution to H. hanleyi View in CoL .

Hanleya nagelfar ( Lovén, 1846) View in CoL is closest to Hanleya hanleyi View in CoL , from which it differs mainly by the greater size but also in part by distribution and minor morphological and ecological features. An in-depth study was carried out by Sirenko et al. (2016), who considered H. nagelfar View in CoL a synonym of H. hanleyi View in CoL , and we agree with their upshots.

Comparisons. See Tab. 7 for a comparison with Hanleya spp . considered in the present study.

Distribution. Upper Miocene: northeastern Atlantic (Tortonian): Ligerian Basin, France: Saint-Clément-de-la-Place ( Dell’Angelo et al. 2018b); Proto–Mediterranean Sea (Tortonian): N. Italy: Borelli, Rio di Bocca d’Asino (Dell’Angelo et al. 1999, 2015a). Lower Pliocene: North Europe, Belgium:Kallo ( Marquet 1984, 2002); northeastern Atlantic: U.K.: Sutton ( Wood 1848; Reid 1890); central Mediterranean, Italy: Liguria: Bussana (this study). Pliocene: northeastern Atlantic, Mondego Basin, Portugal: Vale de Freixo ( Dell’Angelo et al. 2022). Upper Pliocene to lower Pleistocene: northeastern Atlantic (Zanclean): Anjou, France: St. Julien-de-Concelles ( Dell’Angelo et al. 2018b). Pleistocene: central Mediterranean, Italy: Archi S. Francesco, Ficarazzi, Vallone Catrica, Musalà, Salice, Terreti (this study), Capraia Island-Capo Corso ( Dell’Angelo & Giusti 1997), SE06 ( Taviani et al. 2023). Recent: North and Central Atlantic Ocean, near southern Greenland ( Hansson 1998; Sneli & Gudmundsson 2018), North America, Europe ( Kaas 1979; McKay & Smith 1979; Consolado Macedo et al. 1999; Urgorri et al. 2017), Canary Islands ( Kaas 1991; Hernández & Rolán 2011) and northern Africa, Madeira Arch. ( Kaas 1991; Segers et al. 2009); Mediterranean Sea: Italy ( Dell’Angelo et al. 2021a), Aegean Sea ( Zenetos & Van Aartsen 1995), Turkey ( Ozturk et al. 2014) ( Sirenko 2014; Sirenko et al. 2016; Dell’Angelo et al. 2021a).