Eumillipes, Marek, 2021

Marek, Paul E., Buzatto, Bruno A., Shear, William A., Means, Jackson C., Black, Dennis G., Harvey, Mark S. & Rodriguez, Juanita, 2021, The first true millipede- 1306 legs long, Scientific Reports 11 (23126), pp. 1-11 : 1-11

Eumillipes, Marek new genus.

http://zoobank.org/NomenclaturalActs/a258f64e-0d4c-4941-be20-0b5d7 8e1078e.

Type species. Eumillipes persephone Marek , new species.

Generic placement and diagnosis. Te genus Eumillipes is placed in the order Polyzoniida , family Siphonotidae , tribe Rhinotini based on the following characters 10, 20; whether the character is diagnostic for the order (O), family (F), or tribe (T) is denoted in parentheses. Head capsule small, conical, elongated into a sharp snout (O) ( Fig. 1C , Supplementary Fig. S1A–C ). Prozonites and metazonites of trunk rings the same width (O) (Supplementary Fig. S2A ); prozonites not narrow as in the Siphonophorida . Rings smooth (Supplementary Fig. S2B ), covered with neither cuticular ornaments nor long setae as in the Siphonophorida . Vertex of head with two macrosetae (O) (Supplementary Fig. S1C ). Antennae thick with equally sized antennomeres (O) ( Fig. 1C , Supplementary Fig. S3A); antennae not strongly elbowed between antennomeres 3, 4 as in the Siphonorhinidae (Siphonophorida) . Gnathochilarium reduced to three sclerites: mentum; lef, right stipes (O). Ozopores located

(> 180 segments) is well known from the order Siphonophorida , including Illacme plenipes with 192 segments and 750 legs, but it has independently evolved in the Australian order Polyzoniida with Eumillipes persephone bearing up to 1,306 legs and 330 segments. Tis feature (dark branches) has evolved between two and four times in diplopods based on a character state reconstruction using parsimony. Maximum likelihood phylogeny of 312 orthologous sequences with Polydesmida , Stemmiulida , Chordeumatida , Spirostreptida , and Sphaerotheriida as outgroup taxa. Julida, Spirobolida , and other diplopod orders omitted from the analysis. Support values on nodes are bootstrap supports. Numbers in parentheses afer species names are the maximum segment count for the taxon. Species with super-elongation present denoted in bold. Millipede silhouettes sized relative to one other. Diagram created with Adobe Illustrator 2021 (adobe.com/products/illustrator.html).

far in from lateral edges of tergites; placed two-thirds the distance from midline laterally to tergal margins (F) (Supplementary Fig. S2D ). Vasa deferentia open through small conical lobes (penes) on the posterior surfaces of the second leg coxae (F). Telson a complete ring around the anal valves (F) (Supplementary Fig. S2D ). Tarsal claw with long sigmoid-shaped accessory claw at its base that exceeds the claw in length (F) (Supplementary Fig. S1D ). Te genus differs from other siphonotid genera by the following characters. Anterior gonopods (i.e., 9th leg pair) strongly modified with podomeres 3–4 fused, not leg-like as in Siphonotini genera (T) ( Fig. 1C , Supplementary figs. S4, S5A). Apex of anterior gonopods distinctly bifurcated into two processes ( Fig. 1C , Supplementary figs. S4, S5A), not a single process as in the genera Rhinotus Cook, 1896 and Siphonoconus Attems, 1930 .

Figures

Figure 1. Te leggiest animal on the planet, Eumillipes persephone, from Australia. (A) female with 330 segments and 1,306 legs (paratype specimen, T147124). (B) ventral view of legs (male holotype, T147101). (C) dorsal view of head and ventral view of gonopods (male holotype, T147101). Scale bars, 0.5 mm.

Figure 2. Phylogenomic estimation of the evolutionary history of colobognath millipedes. Super-elongation