Iraniulus Attems, 1951

Vagalinski, Boyan & Golovatch, Sergei I., 2021, The millipede tribe Brachyiulini in the Caucasus (Diplopoda, Julida, Julidae), ZooKeys 1058, pp. 1-127 : 1

Genus Iraniulus Attems, 1951

Updated diagnosis.

A genus of the tribe Brachyiulini differing from contribal genera by the unique, complex structure of the solenomere which consists of a basomesal process terminating the flagellum and seminal channels, a basocaudal process, and a branched apical part; as well as by the following combination of other characters: promeres positioned completely anteriorly in relation to opisthomeres; opisthomere with a lamellar basoposterior process ending with a visor-like apical outgrowth protruding mostly caudad, and an anterior process; a lateral process absent or poorly developed, in the shape of a rather weakly pronounced lobe.

General description.

Small to medium-sized Brachyiulini (L (males) = 11-32 mm).

Ommatidia present.

Ozopores right on or tightly behind pro-metazonal suture at least on more anterior body rings.

Epiproct well-developed, markedly long.

Male hypoproct broadly rounded, without setae.

Male mandibular stipites considerably expanded, broadly rounded, anterior/anteroventral corner either indistinct or broadly rounded.

Male walking legs ventrally with two well-developed adhesive pads, one each on postfemur and tibia.

Penis short and stout, with indiscernible or very short apical lobes, as well as small and rounded terminal lamellae.

Gonopods:

In situ protruding from gonopodal sinus only with their apical parts, directed completely ventrad.

Promere as high as opisthomere, with a broad base, more or less narrowing distad and bearing a slender, tapering, apicomesal process.

Opisthomere from rather stout to slender; a basoposterior process mostly vestigial, i.e., present as a weakly pronounced vertical ridge running parallel to CBO, ending with a simple, lamellar, apical outgrowth protruding nearly perpendicular to CBO; anterior process fine and tapering; a lateral process absent or represented by a small lobe; a mesomeroidal lobe absent; solenomere complex, consisting of a tapering basomesal process and several other small processes and lobes apically.

Vulva:

Subcylindrical, mostly symmetrical.

Bursa with a distinct, slightly obtuse to subrectangular, postero-apical margin.

Opening placed right on top of bursa.

Operculum shorter than, to subequal to, bursa.

Receptaculum seminis: central tube narrow, digitiform; posterior tube very narrow, more or less folded; posterior ampulla small to medium-sized.

Remarks.

Vagalinski and Lazányi (2018) referred to the distocaudal projection of the opisthomere in I. fagorum (Attems, 1951), the single known species of the genus at that time, as an apicoposterior process, because of its position and orientation being just like those of the latter process in other Brachyiulini , e.g., in the genera Enghophyllum Lazányi & Vagalinski, 2013 or species of Cyphobrachyiulus and Graecoiulus Vagalinski & Lazányi, 2018. However, SEM micrographs of the gonopods of both I. fagorum and I. tricornis sp. nov. reveal that what have seemed like an apicoposterior process does not originate immediately from the CBO, but is a continuation of the basoposterior process or its apical outgrowth, as denoted in species of the genera Omobrachyiulus and Byzantorhopalum . Also, in the aforementioned paper, the process observed disto-anteromesally on the opisthomere in I. fagorum (Attems, 1951) was called a meso-anterior process, suggesting homology with the similarly positioned process present in another two brachyiulinine genera, Brachyiulus Berlese 1884 and Graecoiulus . Again, from the SEM pictures it becomes clear that the flagellum and seminal channels terminate in that process rather than at the very top of the solenomere. Thus, that process in Iraniulus must be considered as part of the solenomere, unlike the condition observed in Brachyiulus and Graecoiulus , in both of which (as in all remaining Brachyiulini ) the two channels end up at the solenomere apex.