Tag Archives: Helicarionidae

Dupontia affouchensis Griffiths

L’Affouche Dupontio Snail (Dupontia affouchensis)

This species was described in 2000 on the basis of a single subfossil specimen that had been found in 1997 in limestone scree of the Caverne L’Affouche on the island of Rodrigues; the specimen was found together with the bones of tortoises (Cylindraspis sp.) and the Solitaire (Pezophas solitarius (Gmelin)) which both are now likewise extinct. Additional specimens were subsequently found in other caves in the south-west of Rodrigues.

The shells reach heights of about 0.55 cm; they are depressed, thin and pale glossy white with a thin brown band bordering the suture and continuing on the last whorl just above the rounded periphery.

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References:

[1] Owen Lee Griffiths: Nine new species of Mascarene land snails (Mollusca: Gastropoda). Molluscan Research 20(2): 37-50. 2000

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edited: 29.01.2024

Pachystyla waynepagei Griffiths

Page’s Pachystyla Snail (Pachystyla waynepagei)

This species was described in 2000 on the basis of a single subfossil specimen that had been found in 1996 in limestone scree in the Limekiln Cave on the Île aux Aigrettes, Mauritius.

The shell reaches a length of 2.8 cm; it differs from the shells of its close relative, the Two-colored Pachystyla Snail (Pachystyla bicolor (Lamarck)) (see photo below) by lacking a decussate sculpture and by its orange-colored last whorl with a white peripheral band.

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Two-colored Pachystyla Snail (Pachystyla bicolor)

Photo: Simon Tonge
https://www.inaturalist.org/people/simontonge
(public domain)

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References:

[1] Owen Lee Griffiths: Nine new species of Mascarene land snails (Mollusca: Gastropoda). Molluscan Research 20(2): 37-50. 2000

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edited: 29.01.2024

Erepta wendystrahmi Griffiths

Strahm’s Erepta Snail (Erepta wendystrahmi)

This species was described in 2000 on the basis of subfossil material that had been collected in 1989 from limestone scree in the Limekiln Cave on the Île aux Aigrettes, Mauritius.

The shells reach heights of about 0.45 cm; they are depressed conic, solid and pale glossy white.

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References:

[1] Owen Lee Griffiths: Nine new species of Mascarene land snails (Mollusca: Gastropoda). Molluscan Research 20(2): 37-50. 2000

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edited: 29.01.2024

Philonesia weisleri Preece

Weisler’s Philonesia Snail (Philonesia weisleri)

This species was described in 1998.  

The species was endemic to Henderson Island, Pitcairn Islands, and is so far known exclusively from the unique holotype that was found during excavations at Henderson Island’s northern beach.  

The sole known shell reaches a height of about 0,71 cm and a diameter of about 0,83 cm.  

Weisler’s Philonesia Snail was closely related to the Pyramid-shaped Philonesia Snail (Philonesia pyramidalis Preece), but differs from this species by its smaller size, the subglobose shape and the more rounded whorl profile, and by the less flattened, more evenly rounded base of the shell. [1]  

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References:  

[1] R. C. Preece: Impact of early Polynesian occupation on the land snail fauna of Henderson Island, Pitcairn group (South Pacific). Philosophical Transactions of the Royal Society of London B 353: 347-368. 1998  

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edited: 25.10.2017

Zingis radiolata Martens

Taita Snail (Zingis radiolata)

This species, described in 1878, is, or rather was restricted to the Taita Hills in south-eastern Kenya.

The shells reach sizes of about 0,95 cm in height and 1,3 cm in. diameter, they are of a brownish horn color with close, interrupted, whitish rays and a chestnut band on the periphery. [1]

The species could not be recorded during recent surveys and is feared to be already extinct.

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References:

[1] W. Tryon; H. A. Pilsbry; a.o.: Manual of Conchology. Second series: Pulmonata, Vol. 2, Zonitidaelidae 1886

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Depiction from: ‘W. Tryon; H. A. Pilsbry; a.o.: Manual of Conchology. Second series: Pulmonata, Vol. 2, Zonitidaelidae 1886’

(public domain)

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edited: 17.05.2019

Quintalia stoddartii ssp. intermedia Preston

Intermediate Quintalia Snail (Quintalia stoddartii ssp. intermedia)

This subspecies of Stoddart’s Snail was described in 1913; it was restricted to Napean- and Norfolk Island, Norfolk Islands.

This form is now extinct.

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References:

[1] Tom Iredale: The Land Mollusca of Norfolk Island. The Australian Zoologist 11: 46-71. 1945-1951

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Depiction from: ‘Tom Iredale: The Land Mollusca of Norfolk Island. The Australian Zoologist 11: 46-71. 1945-1951’

http://creativecommons.org/licenses/by-nc-sa/3.0

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edited: 17.08.2022

Harmogenanina linophora (Morelet)

(Harmogenanina linophora)

This species was described in 1860; it inhabited the islands of Mauritius and Réunion, Mascarene Islands.

Barely perforate, thin, costulate; corneous brown or greenish, epidermis whitish, chiefly remaining at the suture and below the carina; whorls, 6. Diam. 12 mill.” [1]

Not much else appears to be known about this species, which is now extinct.

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References

[1] George W. Tryon; Henry A. Pilsbry; a. o.: Manual of Conchology. Second series: Pulmonata. Vol 2: Zonitidae. 1886

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Photo: The Trustees of the Natural History Museum, London

https://creativecommons.org/licenses/by/4.0/

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edited: 14.08.2022

Helicarionidae sp. ‘QQsp4’

Te Kou Snail (Helicarionidae sp.)  

The Te Kou Snail is an undescribed species known only from empty shells that were collected in 2005 and 2010 in the upper regions of Takuvaine and Te Kou, two of the mountains in central Rarotonga, Cook Islands.

The species is very likely already extinct now.

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edited: 23.02.2024

Philonesia pyramidalis Preece

Pyramid-shaped Philonesia Snail (Philonesia pyramidalis 

This species was described in 1998.  

The Pyramid-shaped Philonesia Snail was endemic to Henderson Island, Pitcairn Islands, and is known from only three adult subfossil specimens and some apical fragments.  

The shells on average reached sizes of about 0,9 cm.  

The three known specimens differ in the color banding; thus, the Pyramid-shaped Philonesia Snail is believed to have possibly been polymorphic like some of its congeners.  [1]  

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References:  

[1] R. C. Preece: Impact of early Polynesian occupation on the land snail fauna of Henderson Island, Pitcairn group (South Pacific). Philosophical Transactions of the Royal Society of London B 353: 347-368. 1998  

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edited: 25.10.2017