Gulella benthodon van Bruggen, 1980

Cole, Mary L. & Herbert, David G., 2023, Seven new narrowly endemic species of Gulella Pfeiffer, 1856 from eastern South Africa (Gastropoda, Streptaxidae) and status revision for another, European Journal of Taxonomy 900 (1), pp. 1-31 : 4-7

publication ID

https://doi.org/ 10.5852/ejt.2023.900.2299

publication LSID

lsid:zoobank.org:pub:0B4BF469-77A8-4CF9-A006-3B98FF4187D5

DOI

https://doi.org/10.5281/zenodo.8423108

persistent identifier

https://treatment.plazi.org/id/E60087E6-FFA1-FFC7-FDAF-5672FC41FAFD

treatment provided by

Plazi

scientific name

Gulella benthodon van Bruggen, 1980
status

stat. nov.

Gulella benthodon van Bruggen, 1980 stat. rev.

Figs 2–3 View Fig View Fig

Gulella darglensis benthodon van Bruggen, 1980: 17–19 View in CoL , fig. 6 (type locality: Pirie Forest near King Williams Town [R. Godfrey]).

Diagnosis

Shell very small, cylindrical; sculptured with strong axial ribs; apertural dentition eight-fold, including a strong in-running parietal lamella, a large mid-labral complex with a ridge-like upper margin running into aperture with a tooth near lip edge and another further into aperture, and a larger tooth on its lower margin further from lip edge, a low, inset transverse basal tooth to right of centre, an in-running ridge-like basal tooth to left of centre and a large inset bicuspid columella lamella with two ridge-like teeth; umbilicus widely open.

Type material (not examined)

Holotype SOUTH AFRICA – Eastern Cape • Pirie Forest, near King Williams Town [now Qonce]; ca 1920; R. Godfrey leg.; NHMUK 1937.12 About NHMUK .30.781.

Paratype SOUTH AFRICA • 1 spec.; same collection data as for holotype; NHMUK 1937.12 About NHMUK .30.782 .

Material examined

SOUTH AFRICA – Eastern Cape • 5 specs; Hogsback, Auckland Nature Reserve, downstream of Madonna and Child waterfall; 32.60701° S, 26.9625° E; 1043 m a.s.l.; 25 Jan. 2002; D. Herbert, M. Bursey and G. Redman leg.; NMSA W25 About NMSA GoogleMaps 2 specs; Hogsback, Auckland Nature Reserve, Tyume River valley , downstream of Madonna and Child waterfall; 32.6055° S, 26.9603° E; 1030 m a.s.l.; 31 Dec. 2008; M. and K. Cole leg.; NMSA W6660 About NMSA GoogleMaps 2 specs; same collection data as for preceding; ELMD 16135, ELMW 3343 GoogleMaps 1 spec.; same collection data as for preceding; NHMUK 20230166 About NHMUK , ex ELMD 16135 GoogleMaps 1 spec.; same collection data as for preceding; NMW.Z.2023.001.00001, ex ELMD 16135 GoogleMaps 1 spec.; same collection data as for preceding; RMNH.MOL.346278, ex ELMD 16135 GoogleMaps 2 specs; Hogsback, environs of Madonna and Child Waterfall, stn 14-02; 32.6070° S, 26.9625° E; 1043 m a.s.l; 6 Apr. 2014; D. Herbert, L. Davis and M. Cole leg.; NMSA W9731 About NMSA GoogleMaps 1 spec.; Hogsback, Auckland Nature Reserve, Tyume River valley , downstream of Madonna and Child waterfall, south-facing slope; 32.6055° S, 26.9603° E; 1030 m a.s.l.; 4 Jan. 2022; M. Cole leg.; ELMD 19100 GoogleMaps 2 specs; Hogsback, Zinguka area, at base of large boulder near Wolfridge Road; 32.6495° S, 27.0025° E; 1086 m a.s.l.; 4 Jan. 2022; M. Cole leg.; ELMD 18881 GoogleMaps .

Description

SHELL ( Fig. 2 View Fig ). Shell very small, cylindrical, length 3.0– 3.6 mm, width 1.3–1.5 mm, L:W 2.18–2.49 (n = 10). Protoconch approx. 0.9 mm in diameter, comprising approx. 2.5 whorls, smooth; junction between protoconch and teleoconch distinct. Teleoconch comprising nearly four whorls; first two whorls moderately convex, subsequent two more weakly so; whorls with faint subsutural angle delimiting narrow subsutural ramp; sculptured by well-developed axial ribs, extending from suture to suture (approx. 30 on penultimate whorl); rib intervals lacking sculpture ( Fig. 2A–B View Fig ). Aperture sub-quadrate with rounded base and shallowly indented outer lip; dentition eight-fold ( Fig. 2C View Fig ): 1) an oblique, in-running parietal lamella; 2–4) a large mid-labral complex itself with three teeth, its upper margin ridge-like and running into aperture with a tooth near lip edge and another further into aperture, and a larger rounded tooth on its lower margin set back from lip edge; 5) a low, inset transverse basal tooth to right of centre; 6) an in-running ridge-like basal tooth just to left of centre; 7–8) a large inset columella lamella set with two strong ridge-like teeth (there may also be a smaller bump below these, but it is not always obvious). Labral and basal teeth correspond with deep pits behind outer lip. Umbilicus widely open, elongate-oval, with a deep indentation underlying columella lamella ( Fig. 2D View Fig ). Shell almost transparent when fresh, orange-red coloration of dried tissue of animal visible internally.

Distribution ( Fig. 3 View Fig )

Endemic to the Amathole Mountains ; at altitudes between 1000 m and 1100 m above sea level.

Habitat

Amathole Mistbelt Forest (Southern Mistbelt Forest group) ( von Maltitz et al. 2003); in leaf-litter and under logs.

Remarks

We treat Gulella benthodon as a separate species and not as a subspecies of G. darglensis (Melvill & Ponsonby, 1908) as originally proposed. It bears very little resemblance to the other two subspecies of G. darglensis recognised by van Bruggen (1980). It has a large mid-labral complex with three cusps and not a pair of in-running ridge-like labral teeth. The columella lamella also has two strong ridge-like teeth, but both are inset, while in G. darglensis the lower tooth extends almost to the lip edge. The deeply situated columellar teeth were also noted by van Bruggen (1980) and were the origin of the subspecific name. Gulella benthodon has stronger and coarser sculpture than both subspecies of G. darglensis ; G. d. darglensis (Melvill & Ponsonby, 1908) has close-set axial riblets and G. d. illovoensis (Burnup, 1914) is smooth.

The apertural dentition of Gulella benthodon closely resembles that of G. kenbrowni Cole & Herbert, 2022 and G. fordycei Cole & Herbert, 2022 , but G. benthodon stands out at a glance by being strongly ribbed and considerably larger. The multi-toothed columella lamella is also reminiscent of G. aprosdoketa Connolly, 1939 , G. bomvana Cole & Herbert, 2009 and G. tietzae Cole & Herbert, 2009 , but these three species are smooth. The labral complex resembles that of several very small, narrow-range species endemic to Zululand, Gulella genialis (Melvill & Ponsonby, 1903) , Gulella laevorsa Burnup, 1925 and Gulella vallaris (Melvill & Ponsonby, 1907) in Group 9 of Herbert & Kilburn (2004), but none of the latter species have a multi-toothed columella lamella.

Conservation

Gulella benthodon is a narrow-range endemic found only in the Amathole Mountains where, despite fairly extensive collecting efforts throughout the mountain range, it has only been found at three localities. Van Bruggen’s (1980) specimens came from the Pirie Forest near King Williams Town, collected in about 1920. Recently collected specimens are known only from Hogsback and the majority were collected in the Auckland Nature Reserve. In spite of these being protected sites, poaching and illegal harvesting of plant products takes place and there is uncontrolled access of cattle.

NMW

Austria, Wien, Naturhistorisches Museum Wien

RMNH

Netherlands, Leiden, Nationaal Natuurhistorische Museum ("Naturalis") [formerly Rijksmuseum van Natuurlijke Historie]

NMSA

KwaZulu-Natal Museum

NMW

Naturhistorisches Museum, Wien

RMNH

National Museum of Natural History, Naturalis

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Order

Stylommatophora

Family

Streptaxidae

Genus

Gulella

Loc

Gulella benthodon van Bruggen, 1980

Cole, Mary L. & Herbert, David G. 2023
2023
Loc

Gulella darglensis benthodon van Bruggen, 1980: 17–19

Bruggen A. C. van 1980: 19
1980
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