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Figs 65-68 in Revision of Dadagulella gen. nov., the "Gulella radius group" (Gastropoda: Streptaxidae) of the eastern Afrotropics, including six new species and three new subspecies
No full textFigs 65-68. Radulae of Dadagulella gen. nov. species. 65. D. radius radius, Amboni. 66. D. pembensis sp. nov., Ngezi, radula in situ on odontophore, ventral view. 67. D. pembensis sp. nov., Ngezi. 68. D. pembensis sp. nov., Ngezi, teeth from ventral end of radular ribbon. Abbreviations: c = central tooth; ii, iii, and iv = examples of bi-, tri- and quadricuspid teeth respectively. All scalebars = 10 μm.Published as part of Rowson, Ben & Tattersfield, Peter, 2013, Revision of Dadagulella gen. nov., the "Gulella radius group" (Gastropoda: Streptaxidae) of the eastern Afrotropics, including six new species and three new subspecies, pp. 1-46 in European Journal of Taxonomy 37 on page 37, DOI: 10.5852/ejt.2013.37, http://zenodo.org/record/380677
Figs 6-26 in Revision of Dadagulella gen. nov., the "Gulella radius group" (Gastropoda: Streptaxidae) of the eastern Afrotropics, including six new species and three new subspecies
No full textFigs 6-26. Adult shells of Dadagulella radius (Preston, 1910) comb. nov., D. browni (van Bruggen, 1969) comb. nov. and their respective subspecies. 6-20. D. radius comb. nov. s.l. 6-8. D. radius calva (Connolly, 1922): 6. Lectotype, Taru Desert. 7. Taru Desert near Malindi. 8. Near Mombasa. 9-20. D. radius radius: 11. Lectotype, Shimba Hills. 12. Gazi. 13. also Gazi. 14. Diani Beach. 15. Amboni. 16. Kimboza. 17. Mkungwe. 18. Pugu. 19. Mbudya I. 20. Jozani. 21-26. D. browni comb. nov. s.l.: 21. D. browni mafiensis subsp. nov., holotype, Mlula. 22. D. browni semulikiensis subsp. nov., holotype, Semuliki NP. 23-26. D. browni browni: 23. Mwanihana. 24. Mzelezi. 25. Pomene Bay. 26. Holotype, Lake Sibayi (after van Bruggen 1969).Published as part of Rowson, Ben & Tattersfield, Peter, 2013, Revision of Dadagulella gen. nov., the "Gulella radius group" (Gastropoda: Streptaxidae) of the eastern Afrotropics, including six new species and three new subspecies, pp. 1-46 in European Journal of Taxonomy 37 on page 10, DOI: 10.5852/ejt.2013.37, http://zenodo.org/record/380677
Dadagulella delgada Rowson & Tattersfield 2013, comb. nov.
No full textDadagulella delgada (Muratov, 2010) comb. nov. Figs 27, 84; Table 1 Gulella delgada Muratov, 2010: 274, 276-277, figs 37, 39-45. Type material examined None. Type locality “ Mozambique: Cabo Delgado: 1.1 km WNW of lighthouse, 19 km NE of Palma, 10.68883° S, 40.62806° E, alt. 11 m, 24 Nov. 2009, I. V. Muratov.” (Muratov 2010). Other material examined None. Description SHELL (Fig. 27). Medium-sized (3.80 - 4.00 mm high x 1.80 - 1.80 mm wide), of 6.5 - 7.5 whorls. Elongate ovate-acuminate, spire narrowly acuminate (spire angle 43 - 49°). Apex sharply pointed (with axis slightly deviated in one syntype). Embryonic whorls smooth. Later whorls with very few, widely-spaced, flaring, subtriangular, lamella-like ribs (about 7 per mm on penultimate whorl). Sutures very deep. Umbilicus narrowly open. Peristome incomplete parietally. Outer palatal surface of aperture with a depression corresponding to the palatal tooth. Dentition 5-fold, consisting of: one lamella-like parietal tooth; one slab-like palatal tooth, forming a parieto-palatal sinus; one basal denticle; a deep-set columellar baffle and one shallower columellar denticle. Juvenile shells with 3-fold dentition: one parietal lamella; one basal tooth and one columellar thickening. Muratov (2010) found no internal dentition in the upper whorls. Anatomy unknown. Range and habitat At the type locality, vegetation on coral rag (Muratov 2010: 284). Remarks The few, flaring, lamella-like ribs and elongate, narrowly acuminate spire of D. delgada comb. nov. allow it to be separated from other species, including some D. radius comb. nov. s.l. which it resembles in size and dentition.Published as part of Rowson, Ben & Tattersfield, Peter, 2013, Revision of Dadagulella gen. nov., the " Gulella radius group " (Gastropoda: Streptaxidae) of the eastern Afrotropics, including six new species and three new subspecies, pp. 1-46 in European Journal of Taxonomy 37 on page 15, DOI: 10.5852/ejt.2013.37, http://zenodo.org/record/380677
Dadagulella cuspidata Rowson & Tattersfield 2013, comb. nov.
No full textDadagulella cuspidata (Verdcourt, 1962) comb. nov. Figs 31, 59, 84; Table 1 Gulella cuspidata Verdcourt, 1962: 3, 27-28, pl. 3, fig. 2. “ Gulella sp. nov. ” – Verdcourt 1958: 94, 100, fig. 10. Gulella cuspidata – van Bruggen 1969: 71. — Verdcourt 1983: 232. — Richardson 1988: 72. — Verdcourt 1996: 136. — Tattersfield 1998 b: 37. — Tattersfield et al. 1998: 135. — van Bruggen 2000: 233. — Verdcourt 2006: 46. — Rowson & Lange 2007: 31. — Muratov 2010: 277. Type material examined TANZANIA: holotype MRAC.792352: 1 ad., Worlds View, Shume, West Usambara Mts (4.70°S, 38.20°E), in rather dry evergreen forest, leg. B. & L. Verdcourt, Dec. 1956. Other material examined None. Description SHELL (Figs 31, 59). Large (4.30 - 4.80 mm high x 1.80 x 2.50 mm wide), of 7.75 whorls. Ovate-acuminate, spire coeloconoid (spire angle 58°). Apex sharply pointed. Embryonic whorls appear smooth but with fine regular radial striae. Later whorls with relatively few, coarse ribs (about 8 per mm on penultimate whorl). Sutures of intermediate depth. Umbilicus narrowly open. Peristome incomplete parietally. Outer palatal surface of aperture with a furrow-like depression corresponding to the upper palatal tooth. Dentition 6-fold (alternatively recognisable as 5-fold), consisting of: one lamella-like parietal tooth; two palatal teeth, the upper much larger and forming a parieto-palatal sinus; one basal, in-running tooth; and a strong, squarish columellar tooth, running in to form a columellar baffle which is connected to it. Juvenile shells and anatomy unknown. Range and habitat Elevation not stated but probably between 1500-2000 m at the type locality in northeastern Tanzania. Remarks This species differs from D. minareta sp. nov. in having two palatal teeth, in having a basal tooth, in the shape of the parietal tooth, and in size.Published as part of Rowson, Ben & Tattersfield, Peter, 2013, Revision of Dadagulella gen. nov., the " Gulella radius group " (Gastropoda: Streptaxidae) of the eastern Afrotropics, including six new species and three new subspecies, pp. 1-46 in European Journal of Taxonomy 37 on page 20, DOI: 10.5852/ejt.2013.37, http://zenodo.org/record/380677
Dadagulella cresswelli Rowson & Tattersfield 2013, sp. nov.
No full textDadagulella cresswelli sp. nov. urn:lsid:zoobank.org:act: B 3362D6 F- 2118 -4D1 D- 8 B 25-098 E 25 B 0 C 3 B 2 Figs 29, 57, 84; Table 1 Etymology After Pete Cresswell, who collected the specimen. Type material examined TANZANIA: holotype NMW. Z.2012.042.00001: 1 ad., Ngorongoro Crater, Arusha Region, crater rim on southeastern side, heavy rainforest leaf litter, leg. P. L. Cresswell, 2 Jun.1996. Other material examined None. Description SHELL (Figs 29, 57). Medium-sized (3.70 mm high x 1.80 mm wide), of 7.0 whorls. Ovate-acuminate, spire coeloconoid (spire angle 52°). Apex sharply pointed. Embryonic whorls smoothly granulate. Later whorls with relatively fine ribs (13 per mm on penultimate whorl). Sutures shallow. Umbilicus narrowly open. Peristome complete. Outer palatal surface of aperture with a very deep, long, furrow-like depression corresponding to the palatal tooth. Dentition 5-fold, consisting of: one V-shaped parietal tooth; one bifid slab-like palatal tooth, forming a clear parieto-palatal sinus, with the upper cusp projecting into the sinus; a deep-set columellar baffle and two shallower columellar denticles. Shells and anatomy of juveniles unknown. Range and habitat Forest at the type locality in northern Tanzania. The vegetation is presumably of a montane type, since the crater floor is above 1700 m while the rim rises to over 2400 m or higher. Remarks This species is distinctive in its deep, long furrow on the outer palatal surface in combination with the coeloconoid spire and dentition. D. minerata sp. nov. shares these features, but differs in having weaker ribs and less complex dentition. It is the only Dadagulella gen. nov. species thus far collected in the volcanic (as opposed to block-faulted) highlands of Tanzania or Kenya.Published as part of Rowson, Ben & Tattersfield, Peter, 2013, Revision of Dadagulella gen. nov., the " Gulella radius group " (Gastropoda: Streptaxidae) of the eastern Afrotropics, including six new species and three new subspecies, pp. 1-46 in European Journal of Taxonomy 37 on page 18, DOI: 10.5852/ejt.2013.37, http://zenodo.org/record/380677
Dadagulella meredithae Rowson & Tattersfield 2013, comb. nov.
No full textDadagulella meredithae (van Bruggen, 2000) comb. nov. Figs 37, 84; Table 1 Gulella meredithae van Bruggen, 2000: 226-232, figs 1-7. “…an as yet unidentified species from Malawi ” – van Bruggen & Meredith 1984: 165. Gulella meredithae – Rowson & Lange 2007: 31. Type material examined MALAWI: holotype RMNH.59399: 1 ad., Nyika National Park (approx. 10.6°S, 33.8°E), Rumphi District, Juniper Forest, approx. 2100 m alt., leg. H.M. Meredith, 16 Sep. 1983. Other material examined None. Description SHELL (Fig. 37). Small (2.30 - 3.10 mm high x 1.40 - 1.60 mm wide), of 5.5 - “<6” whorls. Ovate-acuminate, although spire (spire angle 58 - 77°) less acuminate than in other Dadagulella gen. nov species. Apex rounded (in holotype) to weakly pointed. Embryonic whorls smoothly granulate. Later whorls with very fine, very numerous ribs (about 27 per mm on penultimate whorl). Sutures of intermediate depth. Umbilicus closed or nearly so. Peristome incomplete parietally. Outer palatal surface of aperture with a depression corresponding to the palatal tooth. Dentition 3-fold to 4-fold, consisting of at least: one lamella-like parietal tooth; one slab-like palatal tooth, not forming a parieto-palatal sinus; and a mammillate columellar baffle. Additional teeth limited to a shallow, weak columellar swelling. Juvenile shells with 2-fold to 3-fold dentition: one parietal tooth; one columellar tooth; and usually one basal tooth (termed labral by van Bruggen 2000). Van Bruggen (2000) showed that earlier sets of dentition are visible through the shells of some transparent juveniles, even in the preceding whorls, suggesting slow or no resorbtion. Anatomy unknown. Range and habitat Montane forest (above 1500 m to around 2450 m) in northern and central Malawi, and adjacent part of Zambia (Chowo Forest). Van Bruggen (2000) suspected it to range into parts of Tanzania adjoining northern Malawi. Remarks This species is distinctive in its small size, very fine, numerous ribs, and dentition. It differs from D. radius comb. nov. s.l. and D. browni comb. nov. s.l. in the lack of a basal tooth or denticle. The apex is rounded in the holotype but more conical in paratypes figured by van Bruggen (2000).Published as part of Rowson, Ben & Tattersfield, Peter, 2013, Revision of Dadagulella gen. nov., the " Gulella radius group " (Gastropoda: Streptaxidae) of the eastern Afrotropics, including six new species and three new subspecies, pp. 1-46 in European Journal of Taxonomy 37 on pages 26-27, DOI: 10.5852/ejt.2013.37, http://zenodo.org/record/380677
Dadagulella browni subsp. mafiensis Rowson & Tattersfield 2013, subsp. nov.
No full textDadagulella browni mafiensis subsp. nov. Figs 21, 54, 84; Table 1 Etymology From Mafia Island, with the final ‘a’ elided for euphony. Type material examined NHMUK.20110174: 1 ad., Mlula, Mafia I. (approx. 7.87° S, 39.76° E), evergreen coastal thicket on clay loam coral rag, leg. Frontier Tanzania, Oct.- Nov. 1990, labelled “ Gulella radius aggreg.” by B. Verdcourt. Other material examined None. Description SHELL (Figs 21, 54). Small (3.30 mm high x 1.80 mm wide), of 6.0 whorls. Ovate-acuminate, spire broadly acuminate (spire angle 65°). Apex conical. Embryonic whorls smoothly granulate. Later whorls with relatively coarse ribs (12 per mm on penultimate whorl). Sutures relatively shallow. Umbilicus narrowly open. Peristome incomplete parietally. Outer palatal surface of aperture with a depression corresponding to the palatal tooth. Dentition 5-fold, consisting of: one lamella-like parietal tooth and one additional parietal denticle; one slab-like palatal tooth, forming a narrow parieto-palatal sinus; one basal denticle; and a deep-set, folded columellar baffle, but no shallower columellar denticles. Shells and anatomy of juveniles unknown. Range and habitat Evergreen coastal thicket at the type locality. Remarks This taxon is in some respects intermediate between the type specimens of D. r. radius comb. nov. and D. b. browni comb. nov., and thus distinct from either, yet difficult to place. It is larger and not as squat as other D. browni comb. nov. s.l., and lacks the additional basal denticle and shallower columellar dentition. Conversely, it has a parietal denticle not seen in D. radius comb. nov. s.l, is smaller and squatter than most D. radius comb. nov. s.l., and has a longer and narrower parieto-palatal sinus than any D. radius comb. nov. s.l. Mafia Island, from which no other Dadagulella gen. nov. are yet known, lies at almost the same latitude (7.8° S) as the apparent northernmost limit of D. b. browni comb. nov. in mainland Tanzania. Given the morphology of this specimen, its latitude and its isolation as an island population, we treat it as a subspecies of D. browni comb. nov.Published as part of Rowson, Ben & Tattersfield, Peter, 2013, Revision of Dadagulella gen. nov., the " Gulella radius group " (Gastropoda: Streptaxidae) of the eastern Afrotropics, including six new species and three new subspecies, pp. 1-46 in European Journal of Taxonomy 37 on pages 13-14, DOI: 10.5852/ejt.2013.37, http://zenodo.org/record/380677
Dadagulella frontierarum Rowson & Tattersfield 2013, sp. nov.
No full textDadagulella frontierarum sp. nov. urn:lsid:zoobank.org:act: 9D028 B 17-9FCB-47 E 8-96 B 1-5901 B 8 E 3 EA 4 E Figs 34, 61, 84; Table 1 Etymology After Frontier Tanzania, the organisation which collected the specimens; given the ending ‘- arum ’ for a feminine noun in the genitive plural. Type material examined TANZANIA: holotype NMW. Z.2003.074.00001: 1 ad., Mtai Forest Reserve (4.87° S, 38.77° E), East Usambara Mts, Muheza District (plot 69/3), submontane forest at 970 m alt., leg. Frontier Tanzania, 8 Mar. 1997. Paratypes NMW. Z.2003.074.00002: 2 ads, data as holotype. Paratype NMW. Z.2003.074.00003: 1 ad., data as holotype. Paratype NMW. Z.2003.074.00004: 1 ad., data as holotype but 7 Mar. 1997. Paratypes NMT: 2 ads, data as holotype. Other material examined None. Description SHELL (Figs 34, 61). Medium-sized (3.15 - 3.40 mm high x 1.80 - 2.05 mm wide), of 4.5 - 5.0 whorls. Ovateacuminate, spire narrowly acuminate (spire angle 68 - 77°). Apex sharply pointed. Embryonic whorls smoothly granulate. Later whorls with few, widely-spaced, coarse ribs (5 - 7 per mm on penultimate whorl). Sutures very deep. Umbilicus narrowly open. Peristome complete, almost detached. Outer palatal surface of aperture with a depression corresponding to the lower palatal teeth. Dentition 6-fold, consisting of: one complex, V-shaped and flaring parietal tooth; three palatal teeth, the lower two larger and set low down on the palatal surface, not forming a parieto-palatal sinus; one basal, in-running denticle; and one shallow but strong, in-running columellar tooth. Shells and anatomy of juveniles unknown. Range and habitat Submontane forest (970 m elevation) in the East Usambara Mountains, northeastern Tanzania. Remarks The complex dentition and detached peristome of D. frontierarum sp. nov. are unlike that of any other Dadagulella gen. nov. species. It is also characteristic for its few whorls, few ribs and sharply pointed apex. Biogeographically a close relationship with other species in and around the East Usambaras would seem likely but there is no strong resemblance.Published as part of Rowson, Ben & Tattersfield, Peter, 2013, Revision of Dadagulella gen. nov., the " Gulella radius group " (Gastropoda: Streptaxidae) of the eastern Afrotropics, including six new species and three new subspecies, pp. 1-46 in European Journal of Taxonomy 37 on page 23, DOI: 10.5852/ejt.2013.37, http://zenodo.org/record/380677
Dadagulella delta Rowson & Tattersfield 2013, sp. nov.
No full textDadagulella delta sp. nov. urn:lsid:zoobank.org:act: BF3 B 1698 - C 8EF-4 B 28-89 A 8-D1 AA 85773 A 42 Figs 35, 72, 76, 81, 84; Table 1 “ Gulella sp. 12” – Tattersfield et al. 2006: 52-53. Etymology From Greek ‘ delta ’, after the letter we originally used as an informal morphospecies name for the species; used as a noun in apposition. Type material examined TANZANIA: holotype NMW.Z.2003.001.00019: 1 ad., Mt. Mwanihana Forest Reserve (7.82°S, 36.83°E), Udzungwa Mts National Park, Kilombero District, forest at 1050 m alt., leg. BR, PT, MBS & CFN, 29 Jan. 2003. Paratype NMW. Z.2003.001.00020: 1 ad., data as holotype but 1200 m alt., 30 Jan. 2003. Other material examined None. Description SHELL (Fig 32). Large (4.20 - 4.30 mm high x 2.10 - 2.40 mm wide), of 6.5 whorls. Ovate-acuminate, spire broadly acuminate (spire angle 56 - 66°). Apex pointed. Embryonic whorls smoothly granulate. Later whorls with coarse, sinuous ribs (12-13 per mm on penultimate whorl). Sutures of intermediate depth. Umbilicus narrowly open. Peristome incomplete parietally. Outer palatal surface of aperture with a depression corresponding to the palatal tooth. Dentition weak, 3-fold (although could be interpreted as 2-fold or 4-fold), consisting of: one lamella-like parietal tooth; one weak palatal tooth, not forming a parieto-palatal sinus; a columellar baffle so deeply set as to be almost invisible in apertural view; and a very weak shallow columellar swelling. Juvenile shells unknown. CEPHALOPODIUM. Pale cream, with pale tentacle retractors. SALIVARY GLANDS (Fig. 72). United, soft, not tumid, elongate, bilobed; each duct leaving at the whitened apex of the lobe and evenly thick throughout. RADULA. Not successfully prepared. GENITALIA (Figs 76, 81). Vas deferens appearing thickened prior to insertion on penis but actually with an elongate, parallel diverticulum. Penial sheath absent. Interior of penis with weak radial pilasters and small rhombic pads. Apical part of penis with a single large hook, associated with a spatulate “scoop” with microscopically serrated tip. Elsewhere in penis, an elongate cluster of short, simple hooks mounted on rhombic pads. Range and habitat Montane forest (1000 - 1200 m) in the Udzungwa Mountains, central Tanzania. Remarks This species is distinctive in its simple and weak dentition, weaker than in any other Dadagulella gen. nov. species except in D. rondoensis (Verdcourt, 1994) comb. nov. and D. conoidea (Verdcourt, 1996) comb. nov. which have a more conical shape. It can be distinguished from Gulella udzungwensis van Bruggen, 2003, which also occurs on Mt. Mwanihana (van Bruggen 2003), by having a more acuminate spire and more pointed apex, deeper sutures, sinuous ribs and no basal tooth.Published as part of Rowson, Ben & Tattersfield, Peter, 2013, Revision of Dadagulella gen. nov., the " Gulella radius group " (Gastropoda: Streptaxidae) of the eastern Afrotropics, including six new species and three new subspecies, pp. 1-46 in European Journal of Taxonomy 37 on pages 24-25, DOI: 10.5852/ejt.2013.37, http://zenodo.org/record/380677
Dadagulella browni subsp. semulikiensis Rowson & Tattersfield 2013, subsp. nov
No full text<i>Dadagulella browni semulikiensis</i> subsp. nov <p>Figs 22, 55, 84; Table 1</p> Etymology <p>From Semuliki.</p> Type material examined <p>UGANDA: holotype NMW.Z.1997.009.00004: 1 ad., Semuliki National Park (00.82°N, 30.16°E), Bwamba County, Bundibugyo District, lowland Guineo-Congolian rainforest (site IIR), approx. 760 m alt., leg. PT & J.A. Allen, 14 Jul. 1996. Paratype NMW. Z.1997.009.00005: 1 ad., data as holotype.</p> Other material examined <p>UGANDA: NMW. Z.1997.009.00006: 1 juv., data as holotype.</p> Description <p> SHELL (Figs 22, 55). Small (3.20 <i>-</i> 3.30 mm high x 1.90 mm wide), of 6.0 <i>-</i> 6.5 whorls. Ovate-acuminate, spire broadly acuminate (spire angle around 67°). Apex pointed. Embryonic whorls smoothly granulate. Later whorls with relatively coarse ribs (around 12 per mm on penultimate whorl). Sutures relatively shallow. Umbilicus closed. Peristome complete. Outer palatal surface of aperture with a depression corresponding to the palatal tooth, and another much weaker one corresponding to the basal tooth. Dentition 8-fold, consisting of: one lamella-like parietal tooth and one additional parietal denticle; one slab-like palatal tooth, forming a long, narrow parieto-palatal sinus; two basal denticles; a deepset columellar baffle and two shallower columellar denticles. Juvenile shell with 3-fold dentition: one parietal lamella; one bifid basal tooth; and one baso-columellar tooth. Anatomy unknown.</p> Range and habitat <p>Lowland Guineo-Congolian forest at the type locality in the valley of the Albertine Rift.</p> Remarks <p> This subspecies is very similar to <i>D. b. browni</i> comb. nov. and, if found together, the two might not at first glance be distinguished. However, <i>D. b. semulikiensis</i> subsp. nov. is approximately 10% taller and wider, has shallower sutures and a more complete peristome. Its parieto-palatal sinus is longer and narrower than that of <i>D. b. browni</i> comb. nov., and does not widen appreciably towards its inner end. The type localities of <i>D. b. browni</i> comb. nov. and <i>D. b. semulikiensis</i> subsp. nov. are over 3000 km apart, in very different biogeographic and climatic regions. Although several snail species are known to range between South and East Africa, most are either species of the coastal strip, or are widely distributed throughout the entire area. <i>Dadagulella</i> gen. nov. has not been recorded from much of the intervening area of East Africa and is represented in the Albertine Rift otherwise only by <i>D. selene</i> (van Bruggen & Van Goethem, 1999) comb. nov. It remains possible that the Semuliki population has descended from <i>D. b. browni</i> comb. nov., introduced by man from Tanzania or further to the south, and that the morphological differences are mainly ecophenotypic. However, in the light of these differences and the great geographic separation, we treat it as a subspecies of <i>D. browni</i> comb. nov. as we do with <i>D. b. mafiensis</i> subsp. nov.</p>Published as part of <i>Rowson, Ben & Tattersfield, Peter, 2013, Revision of Dadagulella gen. nov., the " Gulella radius group " (Gastropoda: Streptaxidae) of the eastern Afrotropics, including six new species and three new subspecies, pp. 1-46 in European Journal of Taxonomy 37</i> on page 14, DOI: 10.5852/ejt.2013.37, <a href="http://zenodo.org/record/3806770">http://zenodo.org/record/3806770</a>
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