Eurhynchoribates, Miko, Ladislav, 2016

Miko, Ladislav, 2016, Oribatid mites (Acarina, Oribatida) from French Guyana: review of the genus Rhynchoribates and description of three new species, Zootaxa 4061 (2), pp. 131-145 : 133

Eurhynchoribates n. gen.

Diagnosis. Prodorsum always bears, laterally at base of the rostrum, pair of large tectopedial areas, framed by Ushaped ridge, covered by row of (sometimes confluent) large tubercles. Both setae in and le inserted on (or very close to) cuticular thickenings, which are often developed as confluent lamellar costulae or semicircular lamellar knob (in), and as round or differently formed interbothridial tubercle (le), respectively. Rostrum margins anteriorly often with row of small teeth, which only rarely concentrate close to level of ro insertions. Rostrum tip often with short projections, tips or lobes, consequently appearing as incised. Anterior margin of notogaster with pair of humeral tubercles behind bothridia, but generally without distinct second pair of tubercles or axial arched ridge with notogastral cristae. Podosoma with (at least rudimentary) pedotectum II, sometimes clearly distinguishable even in dorsal view, but present and visible at least in ventral view as distinct projection bearing at the tip epimeral seta 3c. Most lateral epimeral seta on epimere IV (usually 4e or 4d depending on number of epimeral setae on epimere IV) is not inserted on discidium but rather on longitudinal circumpedal ridge separating discidial area from anogenital region. Genital plates bear always 6 pairs of setae. 2 pairs of anal setae usually very fine and minute, shifted forward so that posterior one (an 1) inserted clearly in anterior half of anal plate, or in the middle at least. Adanal seta ad 2 shifted posteriad, so that distance of insertions ad 1 –ad 2 clearly shorter (up to 2 times) than distance ad2–ad3, ad1 and ad2 inserted completely or nearly in postanal position. In addition, ad1 and ad2 usually similarly developed, stronger and longer than ad 3. Lyrifissure iad always distant from lateral margins of anal opening (apoanal), quite large and oblique, converging anteriad.

Type species: Rhynchoribates borhidii Mahunka, 1986

Other known species: E. acutus Balogh, 1958 n. comb.; E. excelsior Mahunka, 1985 n. comb.; E. genavensium Mahunka, 1997 n. comb.; E. montanus Balogh, 1962 n. comb.; E. obtusus Mahunka, 1985 n. comb.; E. pocsi Mahunka, 1986 n. comb.; E. radula Mahunka, 1983 n. comb.; E. robinsoni Balogh, 1962 n. comb.; E. serratus Balogh, 1958 n. comb.; E. subequalis Balogh, 1962 n. comb.

Remarks. To the genus belong all known paleotropic species, i.e. those described from Africa and Madagascar. Position of R. orientalis Balogh, 1970 from Ceylon within that genus is not clear. The species shares with abovementioned ones some important characters (lamellar and interlamellar cuticular thickenings bearing setae le and ro, presence of humeral tubercles on notogaster, presence of pedotectum II and genital plates with 6 setae, 2 pairs of anal setae shifted forwards), but it has different development of prodorsal ridges (no U-shaped tectopedial areas), notogaster has axial arched ridge with notogastral cristae, and adanal setae ad2 are not significantly shifted posteriad. As description of the species is rather short and incomplete, picture of ventral side is not available and there is no information about legs and leg setation, it is difficult to judge if these differences have generic character. Based on the mentioned characters shared with other paleotropical species (most importantly 6 genital setae and presence of rudimentary pedotectum II), the species is provisionally placed within the newly proposed genus ( E. orientalis Balogh, 1970 n. comb.).