Spirostreptus opinatus

Pimvichai, Piyatida, Enghoff, Henrik & Panha, Somsak, 2009, A revision of the Thyropygus allevatus group. Part 1: the T. opinatus subgroup (Diplopoda: Spirostreptida: Harpagophoridae), Zootaxa 2016, pp. 17-50 : 24

The opinatus subgroup

A subgroup of the Thyropygus allevatus group, characterized by

1. An additional projection on the anterior coxal fold (very small in T. loxia n. sp.) 2. A single femoral spine (exception: T. cristagalli n. sp., which has a double femoral spine) 3. An additional apical lobe (the spatulate lobe) on the telopodite

The opinatus subgroup includes T. opinatus ( Karsch, 1881) , n. comb., T. floweri ( Demange, 1961) , n. comb., T. implicatus ( Demange, 1961) , n. comb., T. inflexus ( Demange, 1989) , n. comb., and eight new species; T. bearti n. sp., T. bispinispatula n. sp., T. bispinus n. sp., T. brachyacanthus n. sp., T. chelatus n. sp., T. cristagalli n. sp., T. erectus n. sp. and T. loxia n. sp.

The subgroup is well-defined by the combination of the characters listed above although one, T. cristagalli , differs by having a double femoral spine. In this regard, T. cristagalli resembles the T. bifurcus subgroup, but it differs from this subgroup in having the spatulate lobe on the telopodite. Thus we prefer to classify this species in the opinatus subgroup.

In addition to the diagnostic character combination, all species in the opinatus subgroup share common characters of head, antennae, mandibles, gnathochilarium, collum, epiproct, paraprocts, hypoproct and first pair of male legs. We therefore give a general description of males of the opinatus subgroup, allowing brevity in the subsequent species descriptions.