Mandarina pallasiana

[Melanie]

The fossil record provides useful information to estimate what island communities were like before human colonization. We examined the species composition of the subfossil land snail fauna of dune deposits at the Yatsuse River, central Chichijima, Ogasawara Islands, and compared it with the species recorded in Chichijima since the nineteenth century. The 22 species in the dune deposits included 13 species that are now extinct in Chichijima. Live specimens of 11 of these extinct species were recorded in the early twentieth century, but no living Mandarina pallasiana and Ogasawarana obtusa Chiba et al., n. sp., have ever been recorded. Age of the sediment, estimated by radiocarbon (14C) dating, was 720 years B.P., and it is possible that these two land snail species became extinct as a result of the impact of human colonization of the island, which started in 1830. Specifically, Ogasawarana obtusa, n. sp., became extinct before the start of taxonomic studies of the land snails of Ogasawara. The sample included Hawaiia minuscula, which is generally now considered a cosmopolitan species introduced from North America. This finding suggests that Hawaiia minuscula is not alien in Ogasawara but indigenous.

DOI: 10.2984/1534-6188(2008)62[137:SLSFMO]2.0.CO;2

[another specialist]

source for above

www.bioone.org/perlserv/?request=get-document&doi=10.2984%2F1534-6188(2008)62%5B137%3ASLSFMO%5D2.0.CO%3B2&ct=1

tinyurl.com/5b5rlf

[another specialist]

Taxonomic revision of the fossil land snail species of the genus Mandarina in the Ogasawara Islands

The taxonomy of extant animal species is often based on biological information that is not normally preserved in fossils. Reducing discrepancies between taxonomy based only on hard tissues and that based on other biological information to a minimal level is crucial in studies focusing on species diversity that integrate extant and fossil material. In the present study, I address this issue using morphological analysis of the endemic Ogasawara Island land snails in the genus Mandarina. I first examine pairwise differences in shell morphology among 39 populations of 15 extant species that were discriminated by differences in their reproductive organs and their phylogenetic relationships. A classification model to assess whether the observed differences in fossil shell characters were inter- or intra-specific was developed by training an artificial neural network (ANN) with the patterns of differences in shell characters among the extant species. The average probability that the trained ANN misclassifies extant forms was 1.4%. The trained ANN was applied to discriminate morphological differences among the Pleistocene-Holocene fossil samples of Mandarina luhuana that occurred in Chichijima and Minamijima. As a result, three species were identified in the samples previously referred to M. luhuana. Mandarina pallasiana, previously treated as a synonym of M. luhuana, is separated, and one new species and one new subspecies are described.

ci.nii.ac.jp/naid/110006532618/

[Deleted]

Mandarina pallasiana

family: Camaenidae

known from subfossil remains from the island of Chichijima in the Ogasawara Islands of Japan

source:

Satoshi Chiba; Tetsuro Sasaki; Hajime Suzuki; Kazuo Horikoshi: Subfossil Land Snail Fauna (Mollusca) of Central Chichijima, Ogasawara Islands, with Description of a New Species. ific Science 62(1):137-145. 2008

see also here:

www.bioone.org/doi/abs/10.2984/1534-6188%282008%2962%5B137%3ASLSFMO%5D2.0.CO%3B2?journalCode=pasc

[surroundx]

Chiba, Satoshi, Sasaki, Tetsuro, Suzuki, Hajime and Horikoshi, Kazuo. (2008). Subfossil Land Snail Fauna (Mollusca) of Central Chichijima, Ogasawara Islands, with Description of a New Species. Pacific Science 62(1): 137-145.

[Melanie]

Louis Pfeiffer's scientific description (1850, in Latin)

archive.org/stream/zeitschriftfrm610184953menk#page/n285/mode/2up

[Melanie]

Mandarina pallasiana (Pfeiffer)
Figures SD, 5E, 5F.
Helix pallasiana Pfeiffer. 1850, p. 67
Helix pallasiana Pfeiffer. Tryon, 1886. p. 131, p1. 44. figs. 49, 50.
Mandarina paliasiana (Pfeiffer). Kuroda. 1930. p. 206. p1. 14. fig. 2.
Mandarina paliasiana (Pfeiffer). Habe. 1969. p. 19, 23. Pl. 1. figs. 1,2.
Mandarina paliasiana (Pfeiffer), Habe, 1973, p. 51. p1. 4, fig. 4.
Mandarina pallasiana (Pfeiffer). Minato, 1978, p. 44. 50, Pl. 4, figs. 9, 10.
Mandarina luhuana forma C (Pfeiffer). Chiba, 1989, p. 232,233,235, 237, fig. 9.3.
Materials. CIBML2007O1 (n = 1), Kitafukurozawa (loc. C8) Chichijima. Ogasawara; CIBML2007O2 (n = 9), Kitafukurozawa (loc. C8)
Chichijima. Ogasawara; UMUT CM18430 (n = 4), Kitafukurozawa (loc. C8) Chichijima, Ogasawara.
Shell morphology.—Shell large, slightly thick for the genus. Spire low. Suture very weakly impressed. Embryonic whorls 1.5—2.0; first whorl smooth. thereafter with a number of fine spiral lines on the surface. Surface of postembryonic shell with a numher of fine spiral lines and fine radial growth lines. Shell white, always with 2—4 brown bands, or uniformly brown without any bands. Body whorl with sharp peripheral angle. Periphery close to the middle of the body whorl. Rather straight outline below periphery of body whorl. Base of shell rather convex. Umbilicus distinctly open. Aperture oblique, slightly compressed above and below periphery, with slightly reflecled outer and basal margins. Columellar and basal lip thickened. Slightly thickened parietal callus extending slightly to left of columella in basal view. Whorls of postembryonic shell 2.7—3.2 in number.

Distribution. — Kominato and Kitafukurozawa. Chichijima. Ogasawara (Holocene).

from

Taxonomic revision of the fossil land snail species of the genus Mandarina in the Ogasawara Islands

Chiba Satoshi
Graduate School of Life Sciences, Tohoku University

ci.nii.ac.jp/lognavi?name=nels&lang=en&type=pdf&id=ART0008518725