Tag Archives: Odontostomidae

Hyperaulax ramagei (E. A. Smith)

Ramage’s Noronha Snail (Hyperaulax ramagei)

Ramage’s Noronha Snail was described in 1890; it is only known from the main island of the Fernando de Noronha archipelago offshore north-eastern Brazil, where they were found to be “imbedded in sandy mud on a raised reef and have a semi-fossilized appearance”. [1]

The species must have gone extinct somewhat prior to their description as many specimens appeared quite fresh and still were bearing an intact periostracum (see photo below).

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The genus contains one additional species, also endemic to the same archipelago, Ridley’s Noronha snail (Hyperaulax ridleyi (E. A. Smith)); this species is still alive today. [2][3]

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Photo from: ‘Rodrigo B. Salvador; Daniel C. Cavallari: Taxonomic revision of the genus Hyperaulax Pilsbry, 1897 (Gastropoda, Stylommatophora, Odontostomidae). Zoosystematics and Evolution 95(2): 453-463. 2019’

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

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References:

[1] H. N. Smith: Mollusca. In: Ridley HN, ed. Notes on the Zoology of Fernando Noronha. Zoological Journal of the Linnean Society 20: 473-570. 1890
[2] A. V. L. Freitas; M. S. Miranda; f. D. Passos: Land snails of the Fernando de Noronha archipelago, Brazil. American Malacological Bulletin 37: 66-69. 2019
[3] Rodrigo B. Salvador; Daniel C. Cavallari; Carl C. Christensen; André V. L. Freitas; Marcel S. Miranda; Flávio D. Passos: The endemic land snails of the Fernando de Noronha archipelago, Brasil. Tentacle 30: 6-8. 2022

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edited: 22.01.2024

Biotocus turbinatus (Pfeiffer)

Turban Snail (Biotocus turbinatus)

This species was described in 1870, it is known from the states of Alagoas and Bahia, Brazil; it is considered extinct in the IUCN Red List without further explanation.

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Despite the species being believed to be extinct, there actually exist specimens in the Muséum national d’Histoire naturelle in Paris, France that apparently were collected alive in 1998 “under humid tree trunks in Pedra Talhada“, long after the assumed extinction date. 

Yet, the species was not found during the most recent searches in 2015. [1]

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References:

[1] Rodrigo B. Salvador; Laurent Charles; Luiz R. L. Simone; Philippe Maestrati: Presumed extinct land snail Megalobulimus cardosoi found again in Pedra Talhada Biological Reserve, north-east Brasil. Tentacle 26: 13-14. 2018

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Photo from: ‘Abraham S. H. Breure; Jonathan D. Ablett: Annotated type catalogue of the Bothriembryontidae and Odontostomidae (Mollusca, Gastropoda, Orthalicoidea) in the Natural History Museum, London. ZooKeys 182: 1-70. 2012’

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

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edited: 30.10.2020

Digerus gibberulus (Burrow)

Humpback Snail (Digerus gibberulus)

This species, described in 1815, is endemic to Brazil; it is now considered extinct, however, the reasons for this assumption appear to be unknown.

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Depiction from: ‘ Depiction from: ‘George W. Tryon; Henry A. Pilsbry; a.o.: Manual of Conchology. Second series: Pulmonata. Vol 14: Oriental Bulimoid Helicidae. Odontostominae. Cerionidae. 1901-1902’  

(public domain)

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edited: 30.10.2020