Oxidus obtusus ( Takakuwa, 1942 )

Anh D. Nguyen, Zoltán Korsós, Kuem-Hee Jang & Ui-Wook Hwang, 2017, A revision and phylogenetic analysis of the millipede genus Oxidus Cook, 1911 (Polydesmida, Paradoxosomatidae), European Journal of Taxonomy 293, pp. 1-22 : 15

Oxidus obtusus ( Takakuwa, 1942)

Fig. 8B

Orthomorpha obtusa Takakuwa, 1942a: 363 , 367, fg. 7.

Oxidus obtusus – Chamberlin & Wang 1953: 6. — Takakuwa 1954: 37. — Jeekel 1963a: 20. — Nguyen & Sierwald 2013: 1295.

Diagnosis

This species can be distinguished by its gonopod femorite being short, very broad gently distad; process h bent upward at tip, like a lamellar sickle; spine z small, obtuse; solenophore large, broad and simple, especially wide at its base; mesal lobule not separated from rounded solenophore tip ( Takakuwa 1942a).

Remarks

This species was described from South Korea ( Takakuwa 1942a). Later, Chamberlin & Wang (1953) reported two ♀♀ in the collection of the American Natural History Museum (New York) from Japan. It is possible that the locality was mislabelled because they stated that those specimens were collected and deposited by Dr. Takakuwa Y. Thus, it is believed that these two ♀♀ were collected from the same locality as the species holotype (South Korea).

Lim (2001) synonymized O. obtusus with O. gracilis . He argued that the two species differ only in the number of postfemoral branches, three in O. obtusus and four in O. gracilis ; in his opinion, such a difference is minor and cannot be used to separate two species. With the two species O. gracilis and O. gigas , those characters are important for species delimitation. It is recommended, therefore, that Oxidus obtusus should be considered a valid species. Examination of further fresh material is needed to confrm that recommendation.

Distribution

South Korea.

Figures

Fig. 8. A. Left gonopod of Oxidus avia (Verhoeff, 1937), lateral view. B. Right gonopod of Oxidus obtusus (Takakuwa, 1942), mesal view. Redrawn from Verhoeff 1937 and Takakuwa 1942 a, respectively. No scale bars.