Centipedes in this genus feature elongate heads, elongate forcipules, and mandibles with long bristles. The second maxillae are connected by only a narrow bridge in the middle of the coxosternite. This coxosternite features processes projecting from the inner corners of the anterior margins and prominent sclerotized ridges. The forcipularsternite features a pair of narrow sclerotized stripes (chitin lines). Pores arranged in a single field appear on sternites on at least the anterior segments of the trunk.
These centipedes range from about 1cm to about 7cm in length and can have as few as 31 or as many as 125 pairs of legs. The small species Ribautia platensis, found in Argentina, measures only 9mm in length and can have as few as 31 leg pairs (31 pairs in males, 31 or 33 in females), the minimum number recorded in this genus. Other small species of Ribautia with notably few legs include the Peruvian species R. williamsi (known from a female specimen measuring 12mm in length with 37 leg pairs), the African species R. paucipes (reaching 15mm in length, with 39 leg pairs in type specimens including both sexes), and the Brazilian species R. onycophaena (reaching 13mm in length, with 39 leg pairs in males and 41 in females). The large species R. taeniata, found in New Caledonia, can reach 75mm in length and can have as many as 125 leg pairs (105 to 121 pairs in males, 111 to 125 in females), the maximum number recorded in this genus.
Phylogeny
A phylogenetic analysis of the orderGeophilomorpha using both molecular data and morphology places a representative of the genus Ribautia in a clade with a sister group formed by representatives of two other genera in the family Geophilidae, Polygonarea and Hyphydrophilus. This phylogenetic tree suggests that these two genera are more closely related to Ribautia than any other genera included in this analysis. These three close relatives form a sister group for a representative of another genus in the same family, Plateurytion, which emerges as the next closest relative included in this analysis. These four close relatives also form a sister group for a representative of another genus in the same family, Steneurytion, which emerges as the next closest relative included in this analysis.
Species
This genus contains more than 50 valid species, including the following:
123Bonato L.; Chagas Junior A.; Edgecombe G.D.; Lewis J.G.E.; Minelli A.; Pereira L.A.; Shelley R.M.; Stoev P.; Zapparoli M. (2016). "ChiloBase 2.0". A World Catalogue of Centipedes (Chilopoda). Rosario Dioguardi and Giuseppe Cortese, University of Padua. Retrieved 24 February 2023.
↑Brolemann, Henry Wilfred (1909). "A propos d'un système des Géophilomorphes". Archives de zoologie expérimentale et générale (in French). 43 (5:3): 303–340 [335–336] – via Biodiversity Heritage Library.
↑Bonato, L.; Chagas Junior, A.; Edgecombe, G.D.; Lewis, J.G.E.; Minelli, A.; Pereira, L.A.; Shelley, R.M.; Stoev, P.; Zapparoli, M. (2016). "Ribautia platensis (Silvestri,1898)". ChiloBase 2.0 - A World Catalogue of Centipedes (Chilopoda). Retrieved 2024-01-20.
↑Silvestri, F. (1898). "Nova Geophiloidea Argentina". Comunicaciones del Museo Nacional de Buenos Aires (in Latin). 1 (2): 39–40 – via Biodiversity Heritage Library.