Lepidochitona tessellata, Dell'Angelo, Lesport, Cluzaud & Sosso, 2020

Dell’Angelo, Bruno, Sosso, Maurizio & Taviani, Marco, 2025, The Cenozoic European Polyplacophora (Mollusca), Zootaxa 5704 (1), pp. 1-377 : 236

publication ID	https://doi.org/10.11646/zootaxa.5704.1.1
publication LSID	lsid:zoobank.org:pub:747DFE8B-156A-493A-8817-5F861C4D6319
persistent identifier	https://treatment.plazi.org/id/03FEF726-FF04-4EFB-0FAD-FC186B5992C8
treatment provided by	Plazi
scientific name	Lepidochitona tessellata
status

Treatment

Lepidochitona tessellata View in CoL Dell’Angelo, Lesport, Cluzaud & Sosso, 2020

Fig. 122 View FIGURE 122

Lepidochitona tessellata View in CoL Dell’Angelo, Lesport, Cluzaud & Sosso, 2020b, p. 15, fig. 10.

Type material. Holotype MHNBx 2020.3.1, tail valve, width 4.3 mm, Figs 122I–L View FIGURE 122 . Paratypes: MHNBx 2020.3.2, head valve, Figs 122A–C View FIGURE 122 ; MHNBx 2020.3.3, intermediate valve, Figs 122E–H View FIGURE 122 .

Type locality. Gaas , Larrat ( France) .

Type stage. Oligocene (Rupelian).

Material examined. Oligocene (Rupelian): Gaas: type material plus Rupelian levels: 6 valves ( BD 944 ); Espibos: 25 valves ( AC, DA, PR); Lagouarde: 6 valves ( AC, DA, PR); Larrat : 119 valves ( AC, DA, JCV, Fig. 122D View FIGURE 122 ). Maximum width of the valves: 4.1 / 7 / 5.1 mm .

Description. Head valve semicircular, posterior margin widely V-shaped, slope almost straight. Intermediate valve broadly rectangular (W/L = 2.17–2.48), rounded in anterior profile, moderately elevated (H/W = 0.41), anterior margin almost straight, lateral margins rounded, posterior margin almost straight, apex not evident, lateral areas evidenced by different sculpture. Tail valve semicircular (W/L = 1.38–1.52), anterior margin straight, mucro subcentral, antemucronal slope slightly convex, postmucronal slope slightly concave just behind mucro.

Tegmentum entirely covered by randomly arranged granules, subrhomboidal in CA and AMA (length 90–100 μm); smaller, roundish in LA and PMA (length ca. 50 μm), some higher tending to form elevated growth lines or groups of isolated granules (some coalescent), giving the impression of forming rough surface. Each granule with many aesthetes of equal size, up to 15 in more elongate granules in CA and AMA, up to 10 in roundish granules in LA and PMA, often one (or more) of them centrally located.

Articulamentum with large apophyses, teeth inequidistant, slit formula 9–11 / 2 / 9–11, eaves spongy.

Remarks. Our material is well preserved, revealing the coarse sculpture of the tegmentum, characteristic for this species.

Comparisons. This species is superficially similar to Lepidochitona oligocaena ( Rolle, 1862) , from which it differs mainly in the different sculpture of LA and PMA, very irregular in L. tessellata Dell’Angelo, Lesport, Cluzaud & Sosso, 2020 with the presence of elevated granules forming growth lines or irregularly distributed groups of higher granules, while in L. oligocaena the granules in these areas are regularly distributed, without any trace of growth lines.

Distribution. Lower Oligocene: northeastern Atlantic (Rupelian): Aquitaine Basin, France: Gaas ( Dell’Angelo et al. 2020b).