Acanthochitona barbarae, Dell’Angelo & Sosso & Taviani, 2024
publication ID |
https://doi.org/ 10.11646/zootaxa.5497.2.2 |
publication LSID |
lsid:zoobank.org:pub:F29D526F-79AC-469B-BA88-3EF640EEA1E1 |
DOI |
https://doi.org/10.5281/zenodo.13618348 |
persistent identifier |
https://treatment.plazi.org/id/039487A1-FF8B-FFDA-FF01-575AEB6AA4D4 |
treatment provided by |
Plazi |
scientific name |
Acanthochitona barbarae |
status |
sp. nov. |
Acanthochitona barbarae View in CoL new species
( Figure 5 View FIGURE 5 )
Type material. Holotype: MZUB 60341 View Materials , intermediate valve, width 3.4 mm ( Figs 5A–D View FIGURE 5 ) ; Paratype 1: MZUB 60342 View Materials , tail valve, width 3.8 mm ( Figs 5E–G View FIGURE 5 ) ; Paratype 2: MNHN-IM-2022-2407, intermediate valve, fragmented ( Fig. 5H View FIGURE 5 ).
Type locality. Western Mediterranean, Tyrrhenian Sea , Sardinia .
Etymology. This species is named after Barbara Gualandi who participated with M.T. in research on marine habitats in the Tyrrhenian Sea and to the collecting at the type locality.
Material examined. Western Mediterranean , Tyrrhenian Sea : S. Lucia (Nuoro province, Sardinia): type material; Tunisia, Kélibia (leg. P. Quadri), one tail valve ( Figs 5I–L View FIGURE 5 ) (lost after SEM photographing). Maximum width 4.2 mm .
Diagnosis. Intermediate valves broadly rectangular, semicarinate, elevated, apex well developed. Whole tegmentum (except JA) sculptured with large and well separated granules of variable size, rounded but truncated by a straight line, elevated, JA finely longitudinally striated and crossed by marked growth lines, each granule with a single subcentral megalaesthete and many micraesthetes. Articulamentum well developed, apophyses strongly protruding, expanded and completely surrounding tail valve, slit formula - / 1 / 2.
Description. Head valve unknown. Intermediate valves broadly rectangular, WT/LT = 1.34, elevated (H/W = 0.38), 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 triangular, much raised. Tail valve circular, WT/LT = 1.07, very elevated, jugal area raised, mucro well evident in subcentral position, antemucronal slope straight, postmucronal slope slightly concave just behind mucro.
Whole tegmentum (except JA) sculptured with large and well separated granules, rounded but truncated by a straight line, elevated, with flat surface, jugal area finely longitudinally striated and crossed by marked growth lines, pectinated in upper edge; granules of variable size, with a single subcentral located megalaesthete and many micraesthetes, mainly grouped near straight line of granules.
Articulamentum well developed, expanded and completely surrounding tail valve, except for jugal margin, apophyses quadrangular and strongly protruding, delimiting a wide jugal sinus, slit formula - / 1 / 2.
Remarks. Acanthochitona barbarae sp. nov. is only known by a few valves from two localities in the central Mediterranean Sea (Sardinia and Tunisia). The valves from Sardinia have the granules rather eroded, the shape seem polygonal, in some cases almost triangular, but the straight line is visible in some better preserved granules, e.g. see PMA in Fig. 5E View FIGURE 5 . It has been hypothesised that A. crinita could represent a «waste basket» containing, in fact, various taxa of still uncertain classification ( Vončina et al. 2023). Their biomolecular research seems to indicate this possibility for two taxa from Croatian waters. Our own study lends support to this view, although only based at present on shell morphological evidence.
Comparisons. The tegmental granules have a particular shape, different from that typical of the other Acanthochitona species known from the Mediterranean, granules small, packed, roundish in A. fascicularis ( Linnaeus, 1767) , granules oval or drop-shaped in A. crinita ( Pennant, 1777) , A. oblonga Leloup, 1981 and A. pilosa Schmidt-Petersen, Schwabe & Haszprunar, 2015 ( Schmidt-Petersen et al. 2015).
Distribution. Western Mediterranean, Sardinia and Tunisia.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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Acanthochitonina |
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