Rhiostoma anceyi Tongkerd & Inkhavilay, 2023
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publication ID |
https://dx.doi.org/10.3897/zookeys.1142.90097 |
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publication LSID |
lsid:zoobank.org:pub:A1129EE5-0F99-41CF-B73A-E771B66E2486 |
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persistent identifier |
https://treatment.plazi.org/id/5A3D8DA2-5C54-45ED-8FD9-4220FBD8E2E3 |
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taxon LSID |
lsid:zoobank.org:act:5A3D8DA2-5C54-45ED-8FD9-4220FBD8E2E3 |
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treatment provided by |
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scientific name |
Rhiostoma anceyi Tongkerd & Inkhavilay |
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sp. nov. |
17. Rhiostoma anceyi Tongkerd & Inkhavilay sp. nov.
Figs 34 View Figure 34 , 38 View Figure 38 , 42C View Figure 42
Type material.
Holotype CUMZ 4494/1 (cW 22.7 mm, cH 11.4 mm, dL 9.7 mm; Fig. 38A View Figure 38 ). Paratypes CUMZ 4374 (9 shells), CUMZ 4465 (4 adults + 1 juvenile), CUMZ 4494/2 (4 shells; Fig. 38B, C View Figure 38 ), CUMZ 4758 (5 adults + 1 juvenile), CUMZ 4887 (3 shells; Fig. 38D View Figure 38 ), CUMZ 10044 (26 adults + 19 juveniles), NHMUK 20220442 (5 shells), and SMF 368677 (5 shells). All paratypes are from the type locality.
Type locality.
Massive limestone karsts in Ban Pha Hom (village), Phoxay District, Vientiane Province, Laos (19°06'27.9"N, 102°22'47.2"E).
Other material examined.
Laos: Near Ban Bokhoun, Boun Neua District, Phongsaly Province: CUMZ 10208 (3 shells; Fig. 38E, F View Figure 38 ).
Diagnosis.
Shell medium to large, thin, and depressed; detached whorl shorter than apertural width. Shell colour uniformly brownish, sometimes with dark zigzag patterns. Periostracum thick and reddish brown. Breathing device with short tubular shape.
Differential diagnosis.
Rhiostom anceyi sp. nov. differs from R. furfurosum sp. nov. by having a tubular breathing device, thickened brownish periostracum, and thickened multi-layered apertural lip. In contrast, R. furfurosum sp. nov. has an incomplete tube breathing device, transparent corneous periostracum, and a thickened, widely expanded apertural lip.
Description.
Shell. Shell medium, cW 19.0-23.5 mm, cH 10.4-13.7 mm, slightly thin, and sub-discoidal shape; detached-whorl length 4-7.5 mm. Apex acute; spire slightly elevated. Whorls 5 to 6, convex, increasing regularly; suture wide and deep; last whorl rounded and stout. Shell surface with fine growth lines. Periostracum thick, corneous, and reddish brown. Shell colour uniformly brownish or with dark brown zigzag pattern; with dark spiral band on periphery. Detached whorl shorter than apertural width and slightly descending. Peristome circular and double; lip thickened and slightly expanded. Aperture opened sub-laterally. Breathing device tubular (sometimes with incomplete tube) and perpendicular to detached whorl; outer lip forming a short and closed tube; inner lip with small hole inside aperture. Umbilicus widely opened and deep. Operculum calcareous, low cup-shaped, and multispiral (Fig. 38 View Figure 38 ).
Radula. Teeth shapes are similar to those of R. asiphon ; only minor variations occur in central tooth, with triangular and dull central cusp. Lateral teeth composed of four cusps, innermost lateral cusp small (Fig. 42C View Figure 42 ).
Etymology.
The species name anceyi is in honour of César-Marie-Felix Ancey (1860-1906), one of the pioneer malacologists who studied the land snail materials from Laos ( Wood and Gallichan 2008).
Distribution.
This new species is known only from Vientiane and Phongsaly provinces, Laos (Fig. 34 View Figure 34 ).
Remarks.
More effort in molecular phylogenetic analysis is required to demonstrate the relationship between this and the other congeners.
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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