Gudeodiscus (Gudeodiscus) messageri messageri (Gude, 1909)

Pall-Gergely, Barna, Hunyadi, Andras, Ablett, Jonathan, Lương, Hao Văn, Fred Naggs, & Asami, Takahiro, 2015, Systematics of the family Plectopylidae in Vietnam with additional information on Chinese taxa (Gastropoda, Pulmonata, Stylommatophora), ZooKeys 473, pp. 1-118 : 24-25

Taxon classification Animalia Stylommatophora Plectopylidae

Gudeodiscus (Gudeodiscus) messageri messageri (Gude, 1909) Figures 5 F–G, 9E, 12 N–Q

Plectopylis messageri Gude 1909, Proceedings of the Malacological Society of London, 8: 214-215., Plate 9, Figs 4, 4 a–b [ “Moung-Hum”, "Nat-Son, Pac-Kha, and Trinh-Tuong"].

Gudeodiscus messageri , - Páll-Gergely & Hunyadi 2013, Archiv für Molluskenkunde 142 (1): 8.

Types examined.

Tonkin, Muong-Hum, leg. Messager, NHMUK 1922.8.29.53 (holotype of Plectopylis messageri , Figure 5F), Tonkin, Nat-Son, leg. Messager, NHMUK 1922.8.29.54 (holotype of messageri var. minor , Figure 5G).

Museum material examined.

Tonkin, coll. Dosch ex Rolle ex Messager, SMF 172088/4; Tonkin, coll. Dosch ex Rolle, SMF 172076/2; Tonkin, Trinh-Tuong, coll. Dosch ex Rolle, SMF 172086/4; Tonkin, Drinch-Tuom (Trinh-Thuong?), coll. Jaeckel ex Messager, SMF 207675/3; Tonkin, alw. Müller, coll. Kaltenbach, SMF 294867/2; Tonkin, Gia-Phu, coll. Dosch ex Rolle, SMF 172089/4; Tonkin, Muong-Bo, coll. Dosch ex Rolle, SMF 172087/4; Tonkin, Muong-Kong, coll. Pfeiffer, K. L. ex Naschloss (?) ex Rolle, January 1938, SMF 102820/1; Tonkin, coll. Dosch ex Rolle ex Messager, SMF 182088/4; Tonkin, Ba-Nat (?), NHMSB 131/200, 122812-122813/2; Pakhé, leg. Messager, MNHN-IM-2012-2129/9; Muong-Hum, leg. Messager, MNHN-IM-2012-2134/15; Nat-Son, Trinh-Thuong, leg. Messager, MNHN-IM-2012-2136/16 ("var. minor "); Muong-Kong, leg. Messager, MNHN-IM-2012-2137/4; Trinh-Thuong, leg. Messager, MNHN-IM-2012-2142/2+4jb; Muong-Hum, leg. Messager, MNHN-IM-2012-2131/5; Muong-Hum, leg. Messager, MNHN-IM-2012-2143/3; Muong-Hum, leg. Messager, MNHN-IM-2012-2145/74; Pakhé, leg. Messager, MNHN-IM-2012-2149/1; Pac-Kha ( Pakhé), leg. Messager, MNHN-IM-2012-2151/10; Nat-Son, leg. Messager, MNHN-IM-2012-2154/6; Muong-Kong, leg. Messager, MNHN-IM-2012-2159/1; Nat-Son, leg. Messager, MNHN-IM-2012-2162/29; Trinh-Thuong, leg. Messager, MNHN-IM-2012-2163/20; Nat-Son, leg. Messager, MNHN-IM-2012-2165/8+25jb; Bac-Kan, leg. Messager, MNHN-IM-2012-2166/6; Bac-Kan, leg. Messager, MNHN-IM-2012-2172/4; Muong-Hum, leg. Messager, MNHN-IM-2012-2173/3; Muong-Hum, leg. Messager, MNHN-IM-2012-2183/4; Pakhé, leg. Messager, MNHN-IM-2012-2184/1; Long-Ping, leg. Messager, MNHN-IM-2012-2186/8; Muong-Hum, leg. Messager, MNHN-IM-2012-2188/8; Bac-Kan, leg. Messager, MNHN-IM-2012-2194/3; Muong-Hum, leg. Messager, MNHN-IM-2012-2196/4; Nat-Son, leg. Messager, MNHN-IM-2012-2198/2; Nat-Son, leg. Messager, MNHN-IM-2012-2199/2; Tonkin, leg. Messager, MNHN-IM-2012-2202/1; Trinh Thuong, leg. Messager, MNHN-IM-2012-2205/12; Muong-Kong, leg. Messager, MNHN-IM-2012-2479/1; Bac-Kan, leg. Messager, MNHN-IM-2012-2475/10; Trinh-Thuong, leg. Messager, MNHN-IM-2012-2472/16; Cao-Bang, leg. Messager, MNHN-IM-2012-2471/1; Tonkin, Pakhé, leg. Messager, MNHN-IM-2012-2458/7; Long-Ping, leg. Messager, MNHN-IM-2012-2457/23; label not readable, leg. Messager, MNHN-IM-2012-2449/2; Bac-Kan, leg. Messager, MNHN-IM-2012-2403/1; Trinh-Thuong, coll. Levazzari, 1929, MNHN-IM-2012-2408/9; Tonkin, coll. Staadt, 1969, MNHN-IM-2012-2411/3; Nat-Son, coll. Letellier, 1949, MNHN-IM-2012-2414/2; Pac-Kha, coll. Letellier, 1949, MNHN-IM-2012-2415/2; Gia-Phu, MNHN-IM-2012-2418/3; Trinh-Thuong, coll. Lavezzari, 1929, MNHN-IM-2012-2419/10; Tonkin, leg. Messager, MNHN-IM-2012-2425/3; Gia-Phu, leg. Messager, MNHN-IM-2012-2215/33; Muong-Hum, leg. Messager, MNHN-IM-2012-2216/3; Long-Ping, leg. Messager, MNHN-IM-2012-2217/9; Trinh-Thuong, leg. Messager, MNHN-IM-2012-2219/12; Col de Nuages, leg. Messager, MNHN-IM-2012-2221/1; Trinh Tuong, leg. Messager, MNHN-IM-2012-2223/2; Tonkin, leg. Messager, MNHN-IM-2012-2225/4; Tonkin, leg. Messager, MNHN-IM-2012-2230/1; Long-Phai, leg. Messager, 1901, MNHN-IM-2012-2237/2; Muang-Kong, leg. Messager, MNHN-IM-2012-2242/3; Nat-Son, coll. Staadt, 1969, MNHN-IM-2012-2282/1; Tonkin, leg. M. Balansa, 1889 July, MNHN-IM-2012-2296/10; Pakhé, leg. Messager, MNHN-IM-2012-2339/1; Bac-Kan, leg. Messager, MNHN-IM-2012-2315/1; Gia-Phu, leg. Messager, MNHN-IM-2012-2364/2; Trinh-Thuong, leg. Messager, MNHN-IM-2012-2379/1; Trinh-Thuong, leg. Messager, MNHN-IM-2012-2394/1; Tonkin, Pac-Kha, NHMUK1916.3.16.15/1; Tonkin, Pac-Kha, coll. Kennard, A.S. ex auct. (Gude), NHMUK 20130620.2/1; Tonkin, Muong-Hum, coll. Biggs, H.E.J. ex Gygngell, 1930, Acc. no. 2258, NHMUK 20130626/2; Tonkin, Gia-Phu, coll. Kennard, A.S. ex auct. (Gude), NHMUK 20130627/2; Tonkin, Muong-Kong, coll. Salisbury ex Beddome, NHMUK 20130628/2; Tonkin, Muong-Kong, 31/3/09, NHMUK 20130629/3; Tonkin, Muong-Hum, 5/1/09, NHMUK 20130630/3; Tonkin, Pac-Kha, 3/11/08, NHMUK 20130631/2 ("var. minor "); Tonkin, 5/1/09, NHMUK 20130632/3; Tonkin, Muong-Hum, coll. Preston, NHMUK 20130633/2; Tonkin, Muong-Bo, 3/11/08, NHMUK 20130634/2 ("var. major "); Tonkin, That-Khé, coll. Salisbury ex Beddome, NHMUK 20130635/1; Tonkin, Muong-Hum, coll. Kennard, NHMUK 20130636/1; Tonkin, Muong-Hum, NHMUK 1909.3.17.29-31/3; Tonkin, Muong-Hum, NHMUK 1916.3.16.16-18/3; Tonkin, Pac-Kha, NHMUK 1909.3.17.32-34/3 ("var. minor "); Tonkin, Pac-Kha, NHMUK 1909.3.17.24-25/2; Tonkin, Muong-Bo, NHMUK 1909.3.17.35-36/2 ("var. major "); Tonkin, Gia-Phee, coll. Rušnov ex Rolle ex Messager, NHMW 92576/1; Tonkin, Trisch-Tuong, coll. Edlauer ex Werner, NHMW 75000/E/7983/2; Tonkin, Muong-Hum, coll. Oberwimmer ex Wagner ex Messager, NHMW 92573/2; Tonkin, Bac-Kan, coll. Oberwimmer, NHMW 71640/O/14028/1; Tonkin, Long-Ping, 3000 m, coll. Oberwimmer ex Wagner ex Messager, NHMW 92572/1; Tonkin, Muong Hum, coll. Rosen ex Messager, NHMW 71640/O/9476/2; Tonkin, Trinh-Tua (?), coll. Rolle, NHMW 92574/2; Tonkin, Ban-Tao, coll. Rušnov ex Blume, NHMW 92575/1; Tonkin, Muong Kong, NHMW 71640/O/46293/2; Tonkin, Nat-Son, coll. Rosen ex Messager, NHMW 71640/O/9477/1; Tonkin, Trisch Tuong, coll. Rušnov ex Rolle ex Messager, NHMW 92578/2; Tonkin, Ban-Lao, coll. Rolle, NHMW 92577/1; Tonkin, Bac-Kan, coll. Oberwimmer, NHMW 92567; Tonkin, Bac-Kan, coll. Oberwimmer, NHMW 103353/1; Tonkin, Nat-Son, coll. Rušnov ex Messager, NHMW 103355/1; Vietnam/132, Lao Cai Province, Cox-Xan, 400 m, leg. Topál & Matskási, 27.11.1971., VA/10.

Diagnosis.

At least one shell was opened of every larger samples. Anterior lamella normal (not dissolved into small denticles); lower parietal plica does not extend beyond the anterior lamella in the anterior direction (Figures 12 N–Q).

Measurements

(in mm). D = 12.75-18.5 (according to the original description).

Differential diagnosis.

Gudeodiscus messageri messageri inhabits northern Vietnam and in many museum samples it is mixed with Plectopylis gouldingi or Plectopylis fallax (synonyms of Gudeodiscus phlyarius ). These two forms have flat shells with a sharp and angled callus, and sometimes with an apertural denticle. Also, the aperture of Gudeodiscus messageri is rather rounded, whereas it is rather elongated in those populations of Gudeodiscus phlyarius (Figures 9D: phlyarius , Figure 9E: messageri ). This allows Gudeodiscus messageri and Gudeodiscus phlyarius to be distinguished without breaking the shell. The lower parietal plica, which does not extend beyond the anterior lamella in the anterior direction, is characteristic of Gudeodiscus messageri messageri (see also Remarks), but almost always extends in " Plectopylis fallax " and " Plectopylis gouldingi ". " Plectopylis verecunda " (synonym of Gudeodiscus phlyarius ) and typical Gudeodiscus phlyarius always have a strong apertural fold. Moreover, the lower parietal plica of the latter usually extends beyond the anterior lamella in the anterior direction. For comparison with Gudeodiscus messageri raheemi ssp. n., see there.

Intrasubpecific diversity.

Low; the shell size, and the relationship between the lower parietal plica and the anterior lamella show some variability (see remarks). The shell and aperture shape are stable characters.

Distribution

(see Figure 43): Only museum material was available for study, which suggested that this species is located along the Chinese (Yunnan) border.

Remarks.

In one sample (MNHN-IM-2012-2215) a specimen had longer lower plica which extended beyond the anterior lamella in the anterior direction.