Monthly Archives: September 2018

Oryzomys antillarum Thomas

Jamaican Rice Rat (Oryzomys antillarum)

The Jamaican Rice Rat was described in 1898; it was restricted to the island of Jamaica.

The species reached a size of about 26 cm (including the tail); it was furthermore described as: “Color. Above rufous sparsely lined with black, brightest on the rump; head suffused with grayish; under parts yellowish, hairs gray at base; tail pale brown above, lighter beneath; hands and feet whitish; ears blackish outside, yellowish inside.“. [1]

In 1872, Small Indian Mongooses (Urva auropunctata (Hodgson)) had been imported to Jamaica to control the likewise introduced rats in the sugarcane plantations; the mongooses, however, were also very effective in eradicating the native rodents. Feral cats and dogs certainly played their part too and finally, in 1877, the Jamaican Rice Rats were seen for the last time.

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References:

[1] Daniel Giraud Elliot: The Land and Sea Mammals of Middle America and the West Indies. Publication of the field Columbian Museum, Zoological Series 4(1). 1904

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Photo from: ”Clayton E. Ray: The Oryzomyine Rodents of the Antillean Subregion. Doctor of Philosophy thesis, Harvard University, 2111 pp. 1962′

(Public domain)

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edited: 29.04.2022

Conozoa hyalina (McNeill)

Central Valley Grasshopper (Conozoa hyalina)

The Central Valley Grasshopper was described in 1901; it is known from only four areas in the Central Valley in California, USA.

“Robust, pale testaceous, almost plain, with a few scattered spots in the middle of the tegmina occupying the usual position of the fuscous bands; anterior and posterior fields plain except for exceedingly faint spots near the base.
…
Length of body, female, 30 mm.; length of tegmina, 30 mm.; length of posterior femora, 18 mm.
….” [1]

The species has not been found since 1953 and is believed to be extinct.

***

syn. Trimerotropis hyalina McNeill

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References:

[1] Jerome McNeill: Revision of the orthopteran genus Trimerotropis. Proceedings of the United States National Museum 23(1215): 393-449. 1901

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edited: 19.08.2022

Dianella sp. ‘Rapa Nui’

Rapa Nui Flax Lilly (Dianella sp.)

This taxon is known from macro-and microfossils that were found in core samples collected in the crater of the Rano Raraku on Rapa Nui, which can be dated to an age of about 9400 to 5400 BCE, which means, that they apparently disappeared prior to the first Polynesian settlement. [1]

The taxon may have been the widespread Polynesian Flax Lilly (Dianella adenanthera (G. Forst.) R. J. F. Hend.) (see photo below) or an endemic species.

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References:

[1] N. Canellas-Bolta; V. Rull; A. Saez; M. Prebble; O. Margalef: First records and potential palaeoecological significance of Dianella (Xanthorrhoeaceae), an extinct representative of the native flora of Rapa Nui (Easter Island). Vegetation History and archaeobotany 23(3): 331-338. 2014

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Photo: Peter de Lange 
http://www.inaturalist.org/people/pjd1

(public domain)

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edited: 11.12.2018

Amastra thaanumi Hyatt & Pilsbry

Thaanum’s Amastra Snail (Amastra thaanumi) 

Thaanum’s Amastra Snail was described in 1911, it was restricted to a place named Ka’a’awa in the Koʻolauloa District on the northeastern coast of O’ahu, Hawaiian Islands.

The species was described on the basis of a single living specimen and several dead shells.

… from the description.:

“The shell is sinistral, imperforate, moderately solid, oblong, having a somewhat silky luster. Spire widely conic with somewhat convex outlines and rather obtuse summit. Embryonic whorls marked with faint, very fine growth-striae only; later whorls distinctly striate obliquely, the striae fine and somewhat thread-like. Upper whorls purplish-brown ith irregular whitish streaks, the last two whorls covered with a rich dark chestnut cuticle, yellowish next the suture, and deciduous in front of the aperture, showing a glossy light green under layer. Aperture rather oblique, livid or bluish white whithin, with a whitish callous rim within the dark-edged lip. Columella short, bearing a strong, triangular, downward-bent lamella. Parietal callus thin.“

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References:

[1] George W. Tryon; Henry A. Pilsbry; a.o.: Manual of Conchology. Second series: Pulmonata. Vol 21: Achatinellidae (Amastrinae). 1911

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Depiction from: ‘ George W. Tryon; Henry A. Pilsbry; a.o.: Manual of Conchology. Second series: Pulmonata. Vol 21: Achatinellidae (Amastrinae). 1911’

(public domain)

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edited: 28.09.2020

Sinployea youngi (Garrett)

Young’s Sinployea Snail (Sinployea youngi)

This species was described in 1872; it was endemic to a single (unknown) valley on the island of Rarotonga, Cook Islands and was described by its author as: “A somewhat rare species, easily known by its wide open umbilicus, few whorls, deep uniform brown color, and plicate striae. On the ground in damp woods, and only noticed in a single valley.“. [1]

The shells reach sizes of about 0,49 cm in diameter; they are: “Widely, perspectively umbilicated, thin, shining, subpellucid, uniform dark brown, closely, obliquely, arcuately, plicately striate, more slightly below, suture channeled; whorls 4 1/2, convex, rapidly increasing, the last deflected above, convex below.” [2]

The species is now extinct.

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References:

[1] Andrew J. Garrett: Descriptions of new species of land and fresh-water shells. American Journal of Conchology 7: 219-230. 1872
[2] G. W. Tryon; Henry A. Pilsbry; a. o.: Manual of Conchology. Second Series: Pulmonata Vol. 3, Helicidae Vol. 1. 1887
[3] Alan Solem: Endodontoid land snails from Pacific Islands (Mollusca: Pulmonata: Sigmurethra). Part II, Families Punctidae and Charopidae, Zoogeography. Field Museum of Natural History Chicago, Illinois 1983

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Depiction from: ‘G. W. Tryon; Henry A. Pilsbry; a. o.: Manual of Conchology. Second Series: Pulmonata Vol. 3, Helicidae Vol. 1. 1887’

(not in copyright)

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edited: 02.08.2022

Laminella venusta (Mighels)

Graceful Laminella Snail (Laminella venusta)  

The Graceful Laminella Snail was described in 1845, it was found in the Mapulehu Valley near the southeastern coast of Moloka’i, Hawaiian Islands.

This species differs from the congeneric Alexander’s Laminella Snail (Laminella alexandri (Newcomb)) and the Depicted Laminella Snail (Laminella depicta (Baldwin)) by its more swollen last whorl and the sunken black markings, which are generally coarser than in L. depicta and which do not form the characteristic patterns.

The shells reach sizes of about 1,35 cm in heigth and 0,62 to 0,73 in diameter.

The animal itself is also mentioned in the description.:

“The animal … is slender, body flesh-color with black puncta down the sides; tentacles very black. When extended, two-thirds as long as the shell.” [1]

***

The Graceful Laminella Snail has three additional color morphs assigned to it, orginally described as varieties, which in fact may well be distinct subspecies: var. muscaria Hyatt & Pilsbry, var. orientalis Hyatt & Pilsbry, var. semivestita Hyatt & Pilsbry. [1]

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References:

[1] George W. Tryon; Henry A. Pilsbry; a.o.: Manual of Conchology. Second series: Pulmonata. Vol 21: Achatinellidae (Amastrinae). 1911

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Depiction from: ‘George W. Tryon; Henry A. Pilsbry; a.o.: Manual of Conchology. Second series: Pulmonata. Vol 21: Achatinellidae (Amastrinae). 1911’ 

(public domain)

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edited: 01.10.2020

Microcolpia parreyssii (Philippi)

Lake Petea Snail (Microcolpia parreyssii)

 

The Lake Petea Snail is one of the few species

in which we can trace the exact course of their extinction.

***

The species was described in 1847, it was restricted to a single relict site, Lake Pețea, a thermal lake with a water temperature of around 42 °C near the town of Oradea in north-western Romania.

The lake is situated above a rich geothermal aquifer, which is known since ancient times, the thermal water has been used to heat a public bath and several houses in the area. It is home to several endemic plant- and animal forms and was declared a nature reserve in 1932. With the beginning of the 2000s the site was found to be heavily polluted with litter; in 2011, the thermal underwater spring suddenly ceased its activity, resulting in an abrupt reduction of the water level and the surface area and in 2015, the lake was reduced to a small pond due to the overexploitation of the thermal aquifer.

In an effort to save the Lake Petea Snail from extinction, several individuals were brought into captivity; in the beginning these individuals reproduced but after some time they began to suffer from a high mortality, and the last surviving snails were finally sent to specialists, but without any success – the species is now extinct. [1]

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References:

[1] Ioan Sîrbu; Adrian Gagiu; Ana Maria Benedek: On the brink of extinction: Fate of the Pețea thermal lake (Romania) and its endemic species. Tentacle 21: 34-37. 2013
[2] Thomas A. Neubauer; Mathias Harzhauser; Elisavet Georgopoulou; Claudia Wrozyna: Population bottleneck triggering millenial-scale morphospace shifts in endemic thermal-spring melanopsis. Paleogeography, Paleoclimatology, Paleoecology 414: 116-128. 2014
[3] Ioan Sîrbu; Ana Maria Benedek: Requiem for Melanopsis parreyssii or the anatomy of a new extinction in Romania. Tentacle 24: 26-28. 2016

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Photo from: ‘Thomas A. Neubauer; Mathias Harzhauser; Elisavet Georgopoulou; Claudia Wrozyna: Population bottleneck triggering millenial-scale morphospace shifts in endemic thermal-spring melanopsis. Paleogeography, Paleoclimatology, Paleoecology 414: 116-128. 2014’

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

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edited: 17.11.2021

Amastra ricei Cooke

Rice’s Amastra Snail (Amastra ricei)

Rice’s Amastra Snail was described in 1917, apparently based on only five recently dead specimens, it was restricted to a small part of the Miloli’i Valley near the northwestern coast of Kaua’i.

The shells reached sizes of about 2,4 cm in heigth and 1,2 to 1,3 cm in diameter.

***

The author of the species also described a variety, named as var. armillata, from the same locality, based on two dead specimens (empty shells) which may be of Pleistocene age or may just have been old surface shells.

This variety differs from the normal form in the following way …:

“… the fourth and fifth whorls are slightly swollen, and the surface is more coarsely but not as closely sculptured with growth-wrinkles. The periphery is distinctly carinated on the last whorl; the carina is margined along its upper edge by a deep narrow sinus. The lower halff of the last whorl descends rather rapidly, with the carina appearing slightly above the suture. The outer margin of the aperture is distinctly modified by the carina. The upper portion being flattened, the lower evenly arched. The columellar fold is weak, thread-like, very oblique and deeply situated.” [1]

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References:

[1] C. Montague Cooke: Some new species of Amastra. Bishop Museum Occasional Papers 3(3): 1-34. 1917

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Depiction from: ‘ C. Montague Cooke: Some new species of Amastra. Bishop Museum Occasional Papers 3(3): 1-34. 1917’

(not in copyright)

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edited: 03.10.2020

Orbexilum macrophyllum (Rowlee) Rydb.

Bigleaf Snakeroot (Orbexilum macrophyllum)

The Bigleaf Snakeroot aka. Large-leaved Leather-root was described in 1919; it is endemic to the Tyron Mountains in North Carolina, USA.

The species has never been found since 1899 when the type material was collected; it may well be extinct.

***

The photo below shows a congeneric taxon, the Eastern Sampson’s Snakeroot (Orbexilum psoralioides(Walter) Vincent), photographed in North Carolina, USA.

Eastern Sampson’s Snakeroot (Orbexilum psoralioides)

Photo: Brandon Wheeler
https://www.inaturalist.org/people/branwhee
(public domain)

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edited: 22.01.2024

Polyscias sechellarum var. contracta F. Friedmann

Bois Banane (Polyscias sechellarum var. contracta)

The Bois Banane (Polyscias sechellarum Baker) is endemic to the Seychelles Islands, where it occurs or occurred on the islands of Curieuse, Félicite, La Digue, Mahé, Praslin, and Silhouette.

The species is split into at least three varieties of which the one discussed here apparently was restricted tot he island of Mahé, from which, however, it was not recorded in recent surveys, it is thus considered most likely extinct. 

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edited: 26.11.2018