Tag Archives: Orthalicidae

Naesiotus jervisensis (Dall)

Jervis Island Snail (Naesiotus jervisensis)

The Jervis Island Snail was described in 1917, it was apparently already extinct at that time, since only dead shells were found.:

A few dead specimens were collected on Jervis Island [Isla Rábida] at an elevation of 900 to 1000 feet.
One or two of these were fresh enough to admit of the hope that living specimens may be secured by some future collector.
” [1]

***

syn. Bulimulus jervisensis Dall

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Photo from: ‘William Healey Dall; Washington Henry Ochsner: Landshells of the Galapagos Islands. Proceedings of the California Academy of Sciences. Ser. 4. Vol. 17.: 141-185. 1928’

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

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References: 

[1] William Healey Dall; Washington Henry Ochsner: Landshells of the Galapagos Islands. Proceedings of the California Academy of Sciences. Ser. 4. Vol. 17.: 141-185. 1928  

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edited: 01.06.2021

Naesiotus alethorhytidus (Dall)

Santa Cruz Snail (Naesiotus alethorhytidus)

This species was described in 1917; it was restricted the southern part of Isla Santa Cruz in the Galapágos Islands and was apparently quite common when it was discovered and described.:

Indefatigable Island, in the moist area on the south side at 350 to 400 feet, and at all attitudes in the interior; (W. H. O.)
This almost comically small and wrinkled species is one of the most interesting finds of the Academy expedition. It is usually pink tipped, with white corrugations and the indentations more or less darkened by volcanic dust.
” [1]

The species was last found alive in 1974 and is thus believed to be possibly extinct.

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References:

[1] William Healey Dall; Washington Henry Ochsner: Landshells of the Galapagos Islands. Proceedings of the California Academy of Sciences. Ser. 4. Vol. 17.: 141-185. 1928

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Photo from: ‘William Healey Dall; Washington Henry Ochsner: Landshells of the Galapagos Islands. Proceedings of the California Academy of Sciences. Ser. 4. Vol. 17.: 141-185. 1928’

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

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edited: 01.06.2021

Naesiotus kublerensis Chambers

Cueva de Kubler Snail (Naesiotus kublerensis)

This species was described in 1986; it is known from subfossil shells that were found amongst a larger collection of shells in the Cueva de Kubler on the island of Santa Cruz in the Galápagos archipelago. [1]

The species was never seen alive and is clearly extinct.

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References:

[1] Steven M. Chambers; David W. Steadman: Holocene terrestrial gastropod faunas from Isla Santa Cruz and Isla Floreana, Galápagos: evidence for late Holocene declines. Transactions of the San Diego Society of Natural History 21(6): 89-110. 1986

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edited: 01.06.2021

Naesiotus saeronius (Dall)

Saeronius Galapagos Snail (Naesiotus saeronius)

This species was described in 1917, it was restricted to the Isla Santa Cruz in the Galápagos archipelago.

The species was last seen in 1974; it could not be found alive during the last recent searches and might thus be extinct. 

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References: 

[1] William Healey Dall; Washington Henry Ochsner: Landshells of the Galapagos Islands. Proceedings of the California Academy of Sciences. Ser. 4. Vol. 17.: 141-185. 1928  

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edited: 01.06.2021

Naesiotus sp. ‘krameri’

Kramer’s Galapagos Snail (Naesiotus sp. ‘krameri’)

This species was described in 1985, its species epithet, however, is now considered a nomen nudum, the reasons therefore are not known to me.

Kramer’s Galapagos Snail appears to have been quite common when it was discovered and described, it was found in all wetlands and in the Scalesia forests north of Cerro Puntudo on the island of Santa Cruz, Galápagos Islands. [1]

The species seems to have not been found alive during the most recent field searches and might be extinct.

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References: 

[1] Guy Coppois: Etude de la spéciation chez les Bulimulidae endémiques de l’archipel des Galápagos (Mollusques, Gastéropodes, Pulmonés). Thèse de Doctorat, Libre de Bruxelles 1-283. 1985

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edited: 01.06.2021

Naesiotus achatellinus Forbes

Achatinella-like Galapagos Snail (Naesiotus achatellinus)

The Achatinella-like Galapagos Snail was described in 1850.

There is no doubt that N. achatellinus is one of the rarer Galápagos land snails. It is of special interest because of its superficial resemblance to certain species of Hawaiian tree snails of the genus Achatinella. Also, its straight-sided, conical shape, its non-impressed, nodulose sutures, and its relatively bright color pattern set it apart from any other known species of Naesiotus from the Galápagos Islands or from the South American mainland.” [2]

The species was found first on Island San Cristóbal in the early 1830s and in 1846; in 1868, it was apparently also found on Isla Española.

The shells reach sizes of about 1,2 to 1,6 cm in height, they are: “perforated, ovate-pyramidal with long, conic spire, rather thin; variously colored, being banded with chestnut on an olivaceous or whitish ground, or chestnut below, white above, always with a white line below the suture; surface smooth and glossy, like an Achatinella with slight growth-wrinkles and an impressed band below the suture, pinched up into tubercles at irregular intervals.” [1]

***

The Achatinella-like Galapagos Snail disappeared from Isla Española at an unknown date and was last seen on Isla San Cristóbal in the 1980s; it is now most likely extinct.

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References: 

[1] George W. Tryon; Henry A. Pilsbry; a.o.: Manual of Conchology. Second series: Pulmonata. Vol 11: American Bulimulidae: Bulimulus, Neopetraeus, Oxychona, and South American Drymaeus. 1897-1898
[2] Allyn G. Smith: New record for a rare Galápagos land snail. Nautilus 85(1): 5-8. 1971

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Depiction from: ‘George W. Tryon; Henry A. Pilsbry; a.o.: Manual of Conchology. Second series: Pulmonata. Vol 11: American Bulimulidae: Bulimulus, Neopetraeus, Oxychona, and South American Drymaeus. 1897-1898’

(public domain)

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edited: 01.06.2021

Naesiotus duncanus Dall

Duncan Island Snail (Naesiotus duncanus)

The Duncan Island Snail was described in 1893, it is restricted to the Isla Pinzón (aka. Duncan Island) in the Galapágos archipelago.

Except the largest specimens of B. nux, these shells are the largest Bulimuli described from the islands.” [1]

The shells reach sizes of about 1,8 cm in height and about 1,1 cm in diameter. [1]

***

The species was never observed alive and is known exclusively from empty shells, thus it certainly was already extinct before it was scientifically described; it probably fell victim to a severe drought. [2]

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References:

[1] George W. Tryon; Henry A. Pilsbry; a.o.: Manual of Conchology. Second series: Pulmonata. Vol 11: American Bulimulidae: Bulimulus, Neopetraeus, Oxychona, and South American Drymaeus. 1897-1898’    
[2] Guy Coppois; Sue Wells: Threatened Galápagos snails. Oryx 21(4): 236-241. 1987

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Depiction from: ‘George W. Tryon; Henry A. Pilsbry; a.o.: Manual of Conchology. Second series: Pulmonata. Vol 11: American Bulimulidae: Bulimulus, Neopetraeus, Oxychona, and South American Drymaeus. 1897-1898’  

(public domain)

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edited: 31.05.2021

Naesiotus arnaldoi (Lanzieri & Rezende)

Arnaldo’s Naesiotus Snail (Naesiotus arnaldoi)

This species was described in 1971; it was endemic to the Ilha da Trindade offshore Brazil; it is apparently known from over 300 specimens.

The shells reach heights of about 0,95 cm.

The species disappeared sometimes during the 1970s due to the destruction of most of the native vegetation by introduced goats. [1]

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References:

[1] Rodrigo B. Salvador; Carlo M. Cunha; Luiz Ricardo L. Simone: Taxonomic revision of the orthalicid land snails (Pulmonata: Stylommatophora) from Trindade Island, Brazil. Journal of Natural History 47(13-14): 949-961. 2013

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edited: 02.05.2022

Bulimulus brunoi (Ihering)

Bruno’s Bulimulus Snail (Bulimulus brunoi)

Bruno’s Bulimulus Snail was described in 1917; it was endemic to the Ilha da Trindade offshore Brazil.

Only the shell of B. brunoi is known; unfortunately, no complete animal has so far been recovered.” [1]

The species disappeared due to the more or less complete destruction of the island’s native vegetation by introduced feral goats. [1]

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References:

[1] Rodrigo B. Salvador; Carlo M. Cunha; Luiz Ricardo L. Simone: Taxonomic revision of the orthalicid land snails (Pulmonata: Stylommatophora) from Trindade Island, Brazil. Journal of Natural History 47(13-14): 949-961. 2013

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edited: 02.05.2022

Naesiotus lycodus (Dall)

Indefatigable Island Snail (Naesiotus lycodus)

The Indefatigable Island Snail was described in 1917, it is, or maybe was, endemic to Isla Santa Crus in the Galápagos Islands.

The species was found on tree trunks at 135 to 165 m elevation. [1]

The Indefatigable Island Snail was apparently not found during the most recent field searches and might be extinct.

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References: 

[1] William Healey Dall; Washington Henry Ochsner: Landshells of the Galapagos Islands. Proceedings of the California Academy of Sciences. Ser. 4. Vol. 17.: 141-185. 1928  

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Photo from: ‘’Abraham S. H. Breure: Annotated type catalogue of the Orthalicoidea (Mollusca, Gastropoda) in the Royal Belgian Institute of Sciences, Brussels, with descriptions of two new species. ZooKeys 101: 1-50. 2011

(under creative commons license (3.0))
https://creativecommons.org/licenses/by/3.0/

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edited: 01.06.2021

Naesiotus sp. ‘nilsodhneri’

Nils Odhner’s Galapagos Snail (Naesiotus sp. ‘nilsodhneri’)

Nils Odhner’s Galapagos Snail was described in 1985, its species epithet, however, is now considered a nomen nudum. 

The species was restricted to the arid zones in the south-east of Isla Santa Cruz in the Galápagos archipelago; it was not found alive during the last recent field surveys and is now feared to be extinct. 

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References: 

[1] Guy Coppois: Etude de la spéciation chez les Bulimulidae endémiques de l’archipel des Galápagos (Mollusques, Gastéropodes, Pulmonés). Thèse de Doctorat, Libre de Bruxelles 1-283. 1985

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edited: 01.06.2021

Naesiotus trogonius (Dall)

Volcano Galapagos Snail (Naesiotus trogonius)

This species was described in 1917, it is endemic to Isla Isabela in the Galápagos archipelago, where it is thought to have inhabited the forests on the slopes of the volcano Ecuador.

The species was not found alive since the 1800s and is definitely extinct.

***

syn. Bulimulus trogonius Dall

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References: 

[1] William Healey Dall; Washington Henry Ochsner: Landshells of the Galapagos Islands. Proceedings of the California Academy of Sciences. Ser. 4. Vol. 17.: 141-185. 1928  

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edited: 01.06.2021

Naesiotus sp. ‘vanmoli’

Van Mol’s Galapagos Snail (Naesiotus sp. ‘vanmoli’)

Van Mol’s Galapagos Snail was described in 1985, its species name is now considered a nomen nudum, however.

The species was endemic to the southwestern part of the island of Santa Cruz in the Galápagos archipelago, where it was found in a narrow area only some 600 m wide in the arid zone at an altitude of about 65 m above sea level. [1]

Van Mol’s Galapagos Snail has not been found during the last field searches; it is thus believed to be most likely extinct. 

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References: 

[1] Guy Coppois: Etude de la spéciation chez les Bulimulidae endémiques de l’archipel des Galápagos (Mollusques, Gastéropodes, Pulmonés). Thèse de Doctorat, Libre de Bruxelles 1-283. 1985

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edited: 01.06.2021

Naesiotus sp. ‘josevillani’

Jose Villan’s Galapagos Snail (Naesiotus sp. ‘josevillani’)

Jose Villan’s Galapagos Snail was described in 1985, its species epithet, however, is now considered a nomen nudum, the reasons therefore are not known to me.

The species was endemic to the Isla Santa Cruz in the Galápagos archipelago, where it was found in the Scalesia forests of the higher altitudes. [1]

Jose Villan’s Galapagos Snail hasn’t been found during the most recent field searches and is thus considered very likely extinct.

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References: 

[1] Guy Coppois: Etude de la spéciation chez les Bulimulidae endémiques de l’archipel des Galápagos (Mollusques, Gastéropodes, Pulmonés). Thèse de Doctorat, Libre de Bruxelles 1-283. 1985

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edited: 01.06.2021

Naesiotus sp. ‘deridderi’

De Ridder’s Galapagos Snail (Naesiotus sp. ‘deridderi’)

This species was described in 1985, its species epithet, however, is a nomen nudum.

De Ridder’s Galapagos Snail occurred in the moister regions of the island of Santa Cruz; the animals apparently had a certain preference for the Arrow-leaved Sida (Sida rhombifolia L.) or the Prickly Sida (Sida spinosa L.), on whose branches they were often found. [1]

The species was not found alive during the last recent field studies and is feared to be extinct.

***

One of the few natural enemies of this species was the Woodpecker Finch (Camarhynchus pallidus (Sclater & Salvin)), which is known to occasionally pick up snails from the plants, which it subsequently beats against a twig or the like until the snail’s body detaches from the shell.  

The reason for the extinction of so many of the endemic snail species of the Galápagos Islands, however, is mainly due to the destruction of their habitats.  

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References:  

[1] Guy Coppois: Etude de la spéciation chez les Bulimulidae endémiques de l’archipel des Galápagos (Mollusques, Gastéropodes, Pulmonés). Thèse de Doctorat, Libre de Bruxelles 1-283. 1985
[2] G. Coppois: Threatened Galapagos bulimulid land snails: an update. In: E. Alison Kay: The Conservation Biology of Molluscs. Occasional Paper of the IUCN Species Survival Commision 9: 8-11. 1995 [3] C. E. Parent; R. P. Smith: Galápagos bulimulids: status report on a devastated fauna. Tentacle 14. 2006 
[4] C. E. Parent; B. J. Crepsi: Sequential colonization and diversification of Galapágos endemic land snail genus Bulimulus (Gastropoda, Stylommatophora). Evolution 60(11): 2311-2328. 2006

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edited: 01.06.2021

Naesiotus blombergi (Odhner)

Blomberg’s Galapagos Snail (Naesiotus blombergi)

Blomberg’s Galapagos Snail was described in 1950 (or 1951 according to other sources) based on 12 specimens that were collected 200 to 300 m above sea level on plants, bushes and trees on the Isla Santa Cruz in the Galápagos archipelago. [1]

The species was apparently last seen alive in 1974; it was not found during the most recent field surveys and is feared to be extinct. 

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References: 

[1] Steven M. Chambers; David W. Steadman: Holocene terrestrial gastropod faunas from Isla Santa Cruz and Isla Floreana, Galápagos: evidence for late Holocene declines. Transactions of the San Diego Society of Natural History 21(6): 89-110. 1986

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edited: 01.06.2021

Naesiotus adelphus Dall

Adelphus’ Galapagos Snail (Naesiotus adelphus)

Adelphus’ Galapagos Snail, described in 1917, is endemic to the Isla Santa Cruz, Galápagos Islands, where it inhabited the island’s arid zones. [1]  

***

Robert P. Smith, a gastropod specialist, investigated the snail populations on six of the larger islands of the Galápagos archipelago in 1970, including Isla Santa Cruz. By 2005 and 2005, when exactly the same areas were investigated again, many populations had disappeared.  

The touristic industry is booming on the islands, particularly on Isla Santa Cruz, and many of the former habitats are destroyed today, not only by development but also by the introduction of foreign species (animals and plants).  

The highlands, formerly home to endemic species like the Galapagos Miconia (Miconia robinsoniana Cogn.) and the Santa Cruz Scalesia (Scalesia pedunculata Hook. F.) are now overrun by introduced plant species, just like the lower regions of the island are.  

The snails are also killed by introduced ants, especially by the Little Fire Ant, also known as Electric Ant, (Wasmannia auropunctata (Roger)). [2][3]

***

Adelphus’ Galapagos Snail was not found in recent years, despite specific searches, and is considered most likely extinct.  

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References:  

[1] William Healey Dall; Washington Henry Ochsner: Landshells of the Galapagos Islands. Proceedings of the California Academy of Sciences. Ser. 4. Vol. 17.: 141-185. 1928 
[2] Christine E. Parent; Robert P. Smith: Galápagos bulimulids: status report on a devastated fauna. Tentacle 14. 2006
[3] Christine E. Parent; Bernard J. Crepsi: Sequential colonization and diversification of Galapágos endemic land snail genus Bulimulus (Gastropoda, Stylommatophora). Evolution 60(11): 2311-2328. 2006  

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Photo from: ‘William Healey Dall; Washington Henry Ochsner: Landshells of the Galapagos Islands. Proceedings of the California Academy of Sciences. Ser. 4. Vol. 17.: 141-185. 1928’

(under creative commons license (3.0))
https://creativecommons.org/licenses/by-nc-sa/3.0/

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edited: 01.06.2021