Plutonium Cavanna, 1881

Schileyko, Arkady A., Vahtera, Varpu & Edgecombe, Gregory D., 2020, An overview of the extant genera and subgenera of the order Scolopendromorpha (Chilopoda): a new identification key and updated diagnoses, Zootaxa 4825 (1), pp. 1-64 : 24

(!) Plutonium Cavanna, 1881

Type species. Plutonium zwierleini Cavanna, 1881 (by monotypy).

Diagnosis. LBS 2–20 with spiracles (figs 5 EG in Bonato et al. 2017). Coxopleuron lacks spine at the place of corresponding process. Prefemur and femur of the ultimate legs lacking spines; pretarsus much longer than tarsal articles taken together and “expanding ventrally in a sclerotized ridge” ( Bonato et al. 2017: 11) i.e. blade-like.

Number of species. 1.

Remarks. Treated as a genus in Di et al. (2010: 51), Edgecombe & Bonato (2011: 395), Bonato et al. (2017: 1); not included in Vahtera et al. (2012a). The most recent morphological account on Plutonium — Bonato et al. (2017) —lacks information on structure of maxillae 2.

As for possible non-monophyly of Plutonium , we agree with Di et al. (2010: 55) who wrote: ”In Plutoniumidae , the morphological analyses … retrieved Theatops as a paraphyletic group, i.e., Plutonium is nested within Theatops ... A three-genus classification … would increase paraphyly rather than lessen it ... We do not place Plutonium in synonymy under Theatops , which would eliminate non-monophyletic taxa from Plutoniumidae …”. That suggestion was confirmed partially by Bonato et al. (2017: 17), who noted that their molecular data did “not decisively favour any of the two alternative hypotheses: (1) Plutonium and Theatops represent two separate lineages, which is consistent with a previous hypothesis elaborated on morphological similarities ( Shelley, 1997) and in agreement with current taxonomy, (2) Plutonium is a derived lineage within Theatops , which is supported also by previous cladistic analyses on morpho-anatomical data”. Because of its unique segmental distribution of the spiracles, we think that Plutonium should be kept as a genus at the moment.