Maorinus

Jałoszyński, Paweł, 2014, Comparative morphology and taxonomy of Sciacharis s. str., Chathamaenus Franz and Maorinus Franz (Coleoptera: Staphylinidae: Scydmaeninae), Zootaxa 3794 (2), pp. 222-236 : 230-231

subgenus Maorinus stat. n.

Maorinus Franz, 1980a: 291 ; replacement name for preoccupied Maoria Franz ; elevated to the genus rank by Kuschel (1990). Maoria Franz, 1975: 14 ; as subgenus of Euconnus , preoccupied, nec Laporte, 1868, nec Pilsbry, 1892, nec Warren, 1912, nec Cameron, 1945. Type species: Phagonophana alacer Broun, 1915 (des. orig.).

Revised diagnosis. A subgenus of Sciacharis that differs from Sciacharis s. str. in internal (adcoxal) part of prothoracic hypomeron anteriorly demarcated from prosternum and posteriorly fused with external part of hypomeron; and in mesoventral intercoxal process continuous, not interrupted in middle, distinctly visible in ventral view in intact specimens as moderately narrow carina with finely setose ventral surface clearly separating mesocoxae.

Remarks. Maorinus (as Maoria ) was described as a subgenus of Euconnus characterized by a strongly convex body and usually long and at least in some places dense and erect setation ( Franz 1975). This diagnosis is certainly highly unclear and matches many species of Euconnus -like Cyrtoscydmini from all continents. Franz (1975) compared Maorinus (as Maoria ) to Euconnus subgenus Tetramelus Motschulsky, 1870 and listed some characters to distinguish these taxa. In my opinion similarities between Maorinus and Tetramelus are only superficial and it remains unclear why Franz associated the morphology of both genera. It is also unclear why Kuschel (1990) elevated Maorinus to the genus rank, and why Franz accepted this decision, in opposition to Magellanoconnus , which was also treated by Kuschel (1990) as a genus (again, without giving any reasons) but retained by Franz (1993, 1997) as a subgenus of Sciacharis .

The morphology of Maorinus , although the general appearance (Figs. 4–5) seems distinct from Sciacharis , is highly similar to structures of Sciacharis s. str. (as shown in Figs. 10–11 , 16–17 and 21 ) and differs in two easily observable details (indicated in Figs. 17 and 21 by arrows). The internal (adcoxal) part of each prothoracic hypomeron is anteriorly strongly narrowing and completely demarcated from prosternum (anteriorly indistinctly separated or even fused with prosternum in Sciacharis s. str.) and the posterior parts of hypomeral ridges are obliterated, so that adcoxal and external parts of hypomera are fused posteriorly (demarcated in Sciacharis s. str.). The mesoventral intercoxal process in Maorinus is not interrupted in middle and forms a long carina distinctly separating mesocoxae. The carina, in contrast to Euconnus , is not expanded ventrally beyond the level of mesocoxae, and the metacoxae are contiguous (broadly separated in Euconnus ).

Species of Maorinus are usually (but not always) larger, more robust, more convex and darker than Sciacharis s. str. Additionally, the vertex in Maorinus can be slightly expanded dorsocaudad, but not strongly and subconically, as in some species of Euconnus ; also the metaventral intercoxal process can be shallowly notched in middle. However, only minor differences in the important structures as the head venter, prosternum and pterothorax were found and they do not justify a separate position of Maorinus as a genus. Therefore, this taxon is here reduced to a subgenus of Sciacharis .

A preliminary study revealed that at least some Australian, New Zealand and New Caledonian species of Sciacharis (Magellanoconnus) do not differ in any important characters from Sciacharis (Maorinus) , but also some of them have slender, and not expanded maxillary palpomere III. However, Magellanoconnus is also distributed in South America and South Africa and its morphology and taxonomic status requires a separate analysis.

Figures

FIGURES 6 – 11. Head capsule of males in dorsal (6, 8, 10) and ventral (7, 9, 11) views: Sciacharis (s. str.) fulva Broun (6 – 7); Sciacharis (s. str.) chathamensis (Franz), comb. n. (8 – 9); Sciacharis (Maorinus) sp. (10 – 11). Abbreviations: bst, basistipes; cd, cardo; clp, clypeal projection; fo, foramen occipitale; fr, frons; gal, galea; gp, gular plate; gs, gular suture; hr, hypostomal ridge; lac, lacinia; lbr, labrum; md, mandible; mn, mentum; mst, mediostipes; mxp, maxillary palpus; oc, occiput; occ, occipital constriction; pp, palpifer; prm, prementum; ptp, posterior tentorial pit; sat, supraantennal tubercle; smn, submentum; tm, temple; vt, vertex.

FIGURES 12 – 17. Prothorax in dorsal (12, 14, 16) and ventral (13, 15, 17) views: Sciacharis (s. str.) fulva Broun (12 – 13); Sciacharis (s. str.) chathamensis (Franz), comb. n. (14 – 15); Sciacharis (Maorinus) sp. (16 – 17). Abbreviations: bst, basisternal part of prosternum; hy, hypomeron; hyr, hypomeral ridge; lp, lateral antebasal pit; mp, median antebasal pit; nss, pronotosternal suture; pcc, procoxal cavity; pcs, procoxal socket; pf, profurca; slc, sublateral carina.

FIGURES 18 – 21. Pterothorax in ventral view: Sciacharis (s. str.) fulva Broun (18); Sciacharis (s. str.) chathamensis (Franz), comb. n. with (19) and without (20) setation; Sciacharis (Maorinus) sp. (21). Abbreviations: ar, anterior ridge; lmfa, lateral mesofurcal arm; mcp, mesocoxal projection; mff, mesofurcal fovea; mscc, mesocoxal cavity; msvp, mesoventral intercoxal process; mtvp, metaventral intercoxal process; pl, posterior lobe; pre, prepectus; si, setose impression; v 3, metaventrite; vlf, ventrolateral foveae.