Humerotegaeus, Colloff, 2023

Colloff, Matthew J., 2023, The oribatid mite superfamily Eutegaeoidea (Acari, Oribatida), with descriptions of new taxa from Australia and New Caledonia and a re-assessment of genera and families, Zootaxa 5365 (1), pp. 1-93 : 39

Humerotegaeus gen. nov.

Type species: Humerotegaeus carinatus sp. nov.

Diagnosis. Medium-sized to large oribatid mites (ca. 650–900 μm long), lamellar cusps with cup-shaped incisions flanked either side by tooth; lamellae relatively narrow: only about as wide as prodorsum. Chelicerae chelate-dentate and of normal proportions. Humeral processes densely rugose, with pointed apices and humeral plates basally; humeral plate either separated from rest of humeral process by anterior invagination or wedge-shaped plate indicated by obtuse anterior and posterior sutures. Bothridial seta long, thin; posterior margin of bothridium lacking anterior condyle of enantiophyses H. With nine pairs of notogastral setae (setae h 1 present) distributed in marginal position. Pedotectum I rectangular in ventral aspect; pd II trapezoid; discidium lobe-like, pointed. Perigenital carina and enantiophysis E4 present. Pre-anal organ T-shaped. The genus can be distinguished from Neoeutegaeus by the following combination of character states: (1) the presence of humeral plates posterior of the humeral processes; (2) the presence of enantiophyses E4 and perigenital carinae; (3) the absence of the anterior condyles of enantiophyses H; (4) the relatively narrow lamellae with pointed cusps; (5) the rugose ornamentation on the humeral processes and (5) the broad, rectangular pedotectum II.

Etymology. this genus is named for the presence of the humeral plates posteriolateral of the humeral processes in the type species. The gender of the genus-group name, with the Latin gender ending - us, latinised from the Greek ending - os, is masculine.

Remarks. Character states of note that distinguish Humerotegaeus from Eutegaeidae are the lamellae, which are relatively short and do not extend beyond the rostrum or cover the entire prodorsum.Their lateral margins are straight and not convex. Also, the fusion of the anteromedian part of the lamellae is not found in eutegaeids. Humerotegaeus is morphologically most similar to Neoeutegaeus , with which it shares the long, pointed, triangular humeral processes with broad bases, lamellar cusps with apical teeth, the presence of perigenital carinae and enantiophyses E4 (also present in Bornebuschia and some species of Porrhotegaeus , Dicrotegaeus and Compactozetes ), short, narrow epimeral plates II, a lobe-like discidium, incomplete posterior margins of epimeral plates IV and notogastral setae of the l and h series in the marginal position. Humerotegaeus spp. also differs from Neoeutegaeus spp. by the rugose ornamentation on the humeral processes and the T-shaped pre-anal organ. The presence of humeral plates on the lateral margins of the notogaster posterior of the humeral processes is a generic autapomorphy in the Neoeutegaeidae .