Pyrgoniscus Kinahan, 1859

Lillemets, B. & Wilson, G., 2002, Armadillidae (Crustacea: Isopoda) from Lord Howe Island: New Taxa and Biogeography, Records of the Australian Museum 54, pp. 71-98 : 86

Pyrgoniscus Kinahan, 1859

Pyrgoniscus Kinahan, 1859: 134 .

Merulana Budde-Lund, 1913 .

Type species. Pyrgoniscus cinctutus Kinahan, 1859 , by monotypy.

Diagnosis. Body dorsoventrally flattened with horizontal epimera; conglobation imperfect owing to folding body, leaving flange along sides; frontal lamina raised well above vertex, with or without midline cleft; epimera 1–2, sometimes 1–3, with tooth-like endolobes close to tergite junction; epimera 2–7 and pleura 3–5 ridged; pleotelson hourglass shaped; uropod protopod distally narrow rectangular, proximal part short; uropod exopod present, well developed.

Remarks. Pyrgoniscus , with an uncertain composition, includes 19 species with representatives in Africa, Madagascar and the Australasian region. The above diagnosis is derived from the original diagnosis by Kinahan (1859) and our new observations. Pyrgoniscus was created by Kinahan (1859) for the species P. cinctutus from “the Eastern Seas”. Stebbing (1900) later considered Pyrgoniscus a synonym of Cubaris Brandt, 1833 . Budde-Lund (1904) placed cinctutus in his “section X” of Spherillo and later renamed the section Merulana , a subgenus of Spherillo ( Budde-Lund, 1913) . Verhoeff (1926) elevated Merulana to a genus, which was retained by Vandel (1973). Monod (1935) and Ferrara (1977) consider Merulana to be a junior synonym of Pyrgoniscus . A.J.A. Green (pers. comm. in Lewis, 1998a,b) disagreed that the described Australian species of Merulana belong in Pyrgoniscus . Our preliminary phylogenetic analysis of some species in these two genera finds Merulana boydensis Lewis, 1998a nested within Pyrgoniscus , suggesting that the two genera may not be distinct. Ultimately, an examination of the type species for both genera will allow a decision on this uncertainty. Several species currently placed in Pyrgoniscus are quite different from the type species, so the monophyly of the genus is uncertain. A comprehensive revision is therefore needed.

Nevertheless, the current species Pyrgoniscus scopelicus n.sp. mostly agrees with the original diagnosis of the genus. This new species lacks the medial cleft of the frontal lamina indicated in the original diagnosis. Three other species without a cleft frontal lamina have previously been placed in Pyrgoniscus , P. lanceolatus Ferrara, 1977 ( Kenya) , P. petiti Monod, 1935 ( Madagascar) and P. intermedius Lewis, 1998b (Lord Howe Island). Two separate groups occur within this genus, based on the presence or absence of a cleft frontal lamina. Pyrgoniscus scopelicus lacks endolobes on epimera 3, which are present in the original type species. Many species placed in Pyrgoniscus also lack endolobes on epimera 3, including P. petiti Monod, 1935 ( Madagascar) , P. hispida ( Vandel, 1973) (NSW) , P. canaliculatus ( Budde-Lund, 1904) (Chatham Island), P. intermedius Lewis, 1998b (Lord Howe Island), P. bicarinatus (Budde- Lund, 1913) (NSW, Queensland) and P. iniquus (Budde- Lund, 1904) (Queensland).

Seven other species from the Australasian region have been placed in Pyrgoniscus : P. impressifrons ( Budde-Lund, 1904) (NSW) ; P. chathamensis ( Budde-Lund, 1885) (Chatham Island); P. carinatus ( Verhoeff, 1926) , P. noduligerus ( Verhoeff, 1926) , P. translucidus gracilior ( Verhoeff, 1926) , P. translucidus translucidus ( Budde-Lund, 1885) and P. exilis ( Budde-Lund, 1885) ( New Caledonia). Merulana rugosa ( Budde-Lund, 1913) , also from Queensland, has been classified in Pyrgoniscus ( Monod, 1935; Ferrara, 1977).