Pearsonia tembatensis Marzuki &amp; Clements 2013, new species
Creators: name: Marzuki, Mohammad Effendi bin
name: Clements, Gopalasamy Reuben
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Fabales
Fabaceae
Pearsonia
Pearsonia tembatensis

description: <i>Pearsonia tembatensis</i>, new species (Figs. 1, 2) <b> <i>Material examined</i>.</b> — Holotype – 1 ex. SH. 8.6 mm × SW. 23.8 mm (ZRC. MOL.3074), on leaf litter near waterfall, Tembat Forest Reserve (5°03'55.9"N, 102°31'31.9"E), Terengganu, Peninsular Malaysia, coll. M. E. Marzuki &amp; R. Clements, May 2011. Paratype — 1 ex. SH. 11.8 mm x SW. 27.0 mm (ME2011 /0186), on leaf litter, Tembat Forest Reserve (5°03'55.9"N, 102°31'31.9"E), Terengganu, Peninsular Malaysia, coll. M. E. Marzuki &amp; R. Clements, May 2011. <b> <i>Diagnosis</i>.</b> — Shell medium-sized, widely umbilicated, dextral, rather thick. Colour brown, translucent, shiny, crossed by narrow peripheral band. Whorls five, slowly increasing; periphery rounded. Radial sculpture ornamented with fine, irregularly growth lines below suture and around umbilicus; spiral sculpture absent. Apex smooth, more or less rounded with inconspicuous growth lines. Wrinkled, irregular diffuse blotches appear after 3½ whorl, becoming inconspicuous after 4½ whorls. Spire flatly discoid, very low, slightly raised above body whorl, ornamented with faint, pale brown stripe at 4½ whorl. Suture deeply impressed; sutural tube short, opening slightly backwards behind peristome, about 2 mm in length. Aperture circular, oblique, white with double peristome; inner thickened while outer peristome reflected and expanded at suture forming an open descending wing identical to <i>Pterocyclos</i>. Operculum corneous, roundly convex, multispiral, ciliated on raised edge, smooth at centre. Animal grey, spotted, foot light brown. <b> <i>Etymology</i>.</b> — This new species is named after its type locality, Tembat Forest Reserve, Terengganu. We chose this name to highlight the biological importance of this forest reserve, portions of which are currently being cleared for a dam. <b> <i>Remarks</i>.</b> — Based on our comparisons with a fairly complete collation of cyclophorid literature (i.e., Morlet, 1892; Kobelt, 1902, 1908; Gude, 1921; Yen, 1939), we assigned our new species to the genus <i>Pearsonia</i> based on a general agreement with the original shell description in German (translated by F. Köhler) by Kobelt (1902): “Shell discoid, with thick, sometimes hairy periostracum. Aperture circular with thin small tubular pore behind the lip opening backwards. Operculum, non-calcareous, multispiral, outside convex, inside flat. Outer whorls flaring.” <i>Pearsonia</i> (and our new species) can be differentiated from <i>Pterocyclos</i> (Benson, 1832) and <i>Crossopoma</i> (Martens, 1891) by the presence of a sutural tube just behind the aperture (Kobelt, 1902; Gude, 1921). <i>Pearsonia</i> is clearly distinct from <i>Cyclotus</i> (Swainson, 1840), which does not have a sutural tube. Although both <i>Pearsonia</i> and <i>Opisthophorus</i> (Benson, 1851) possess a sutural tube, the tube of the latter genus is significantly longer, and turns either upwards or downwards as it decreases in length. Unlike <i>Pearsonia</i> (Godwin-Austen, 1889; Stoliczka, 1872), the edges of the operculum in <i>Cyclotus</i> and <i>Opisthophorus</i> are not raised. There is no other representative of <i>Pearsonia</i> from Malaysia for comparison. Among Malaysian cyclophorids, <i>P. tembatensis</i> new species, has the closest affinity with <i>Cyclotus umbraticus</i> Benthem-Jutting, 1949 from Larut hill [Pahang], but again, the latter species does not have a sutural tube and its shell sculpture has a zigzag-like pattern. Within <i>Pearsonia</i>, <i>P. tembatensis</i> is closely related to <i>P. putaoensis</i> (Godwin-Austen, 1915) and <i>P. minimum</i> (Godwin-Austen, 1915) from the Indian region. However, the shells of the latter two species are significantly smaller and their shell sculpture comprises fine transverse striae on the epidermis. Furthermore, the outer peristome of <i>P. minimum</i> is very simple and only slightly reflected. We hope that future phylogenetic studies incorporating molecular, conchological and anatomical data on cyclophorids will include this new species in order to validate our hypothesis. Based on the geographical distribution of <i>Pearsonia</i>, it is highly likely that our new species belongs to this genus. To date, there are 22 species in the genus <i>Pearsonia</i> found mostly within the Indo-Malayan region. This new species represents the southernmost extent of <i>Pearsonia</i> ’s distribution in Indo-Malaya (Fig. 3).
description: Published as part of <i>Marzuki, Mohammad Effendi bin &amp; Clements, Gopalasamy Reuben, 2013, A New Species Of Cyclophorid Snail (Mollusca: Prosobranchia) From Terengganu, Peninsular Malaysia, pp. 21-24 in Raffles Bulletin of Zoology 61 (1)</i> on pages 22-23, DOI: 10.5281/zenodo.4509293
description: {"references": ["Morlet, L., 1892. Diagnoses Molluscorum novorum, in Indo-China collectorum. Journal de Conchyliologie, 40: 82 - 86.", "Kobelt, W., 1902. Das Tierreich-Cyclophoridae. Koniglich Preussischen Akademie der Wissenschaften zu Berlin, R. Friedlander &amp; Sohn, Berlin. 662 pp.", "Kobelt, W., 1908. Die gedeckelten Lungenschnecken (Cyclostomacea). Systematisches Conchylien-Cabinet von Martini und Chemnitz, 1: 712 - 980, pls. 104 - 144.", "Gude, G. K., 1921. Mollusca III Land Operculates (Cyclophoridae, Truncatellidae, Assimineidae, Helicidae). The Fauna of British India including Ceylon and Burma. Taylor &amp; Francis, London. 386 pp.", "Yen, T- Ch., 1939. Die Chinesischen Land-und Susswasser- Gastropoden des Natur-Museums Senckenberg. Abhandlungen der Senckenbergischen naturforschenden Gesellschaft, 444: 1 - 233 + 16 pls.", "Martens, E. von, 1891. Landschnecken des Indischen Archipels. Zoologische Ergebnisse einer reise in Niederlandisch Ost- Indien, 2: 209 - 264.", "Swainson, W., 1840. A Treatise of Malacology: The Natural Classification of Shell and Shell-Fish. New-Street-Square, London. 419 pp.", "Godwin-Austen, H. H., 1889. On a collection of land-shells made in Borneo by Mr. A. Everett, with descriptions of supposed new species. Part 1. Cyclostomacae. Proceedings of the Zoological Society of London: 332 - 355, pls. 35 - 39.", "Stoliczka, F., 1872. On the land shells of Penang Island, with descriptions of the animals and anatomical notes; part first, Cyclostomacea. Journal of Asiatic Society of Bengal, 41: 261 - 271, pl. 10.", "Godwin-Austen, H. H., 1915. Zoological results of the Abor Expedition: Mollusca III, Cyclophoridae (in part). Records of the Indian Museum, 8: 494 - 503, pls. 38 - 40."]}