Eutegaeoidea Balogh 1965
Creators: name: Colloff, Matthew J.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Nemertea
Pilidiophora
Heteronemertea

description: Eutegaeoidea J. Balogh, 1965
Eutegaeoidea J. Balogh, 1965, p. 59.
Diagnosis. Monodactylous; hysterosoma distinctly wider than long, less than twice length of prodorsum; lamellae very broad, cusped, rounded or transverse and fused apically, typically overlapping lateral margins of prodorsum; bothridia long, cylindrical or horn-shaped or fused with lateral prodorsum, projecting anterolaterally and with internal spiral thickening; bothridial seta long, typically setiform or bacilliform. Prodorsum posterior of bothridia often conspicuously waisted and narrow in adults and immatures. Humeral processes short and triangular or long, pointed, projecting anteriorly beyond level of bothridia but typically not bearing setae (except Porrhotegaeus catherinae sp. nov.; cf. below); dorsosejugal scissure transverse; cerotegument commonly present; notogastral integument smooth, never sculptured, with seven to ten pairs of setae. Circumpedal carina typically present (absent in Cerocepheidae and Bornebuschiidae fam. nov.). Perigenital carinae, enantiophyses E4 and complete or partial enantiophyses H, B and V present or absent. With five to seven pairs of genital setae and two or three pairs of adanal setae. Immatures eupheredermous, lacking central gastronotic setae of the d series in the nymphal stages; sometimes with flat, elaborate scales from which marginal setae emerge.
Remarks. A checklist and classification of the Eutegaeoidea, based on the present work (Table 2), includes seven families, 14 genera and 84 species; Eutegaeidae: Eutegaeus (21 spp.); Neseutegaeus (6 spp.); Atalotegaeus (6 spp.); Neoeutegaeidae fam. nov.: Humerotegaeus gen. nov. (2 spp.); Neoeutegaeus (7 spp.); Compactozetidae: Compactozetes (10 spp.); Hamotegeus (4 spp.); Sadocepheus (14 spp.); Bornebuschiidae fam. nov.: Bornebuschia (2 spp.); Dicrotegaeus (3 spp.); Pterozetidae: Pterozetes (2 spp.); Dudichella (1 sp.); Porrhotegaeidae fam. nov.: Porrhotegaeus (4 spp.); Cerocepheidae: Cerocepheus (2 spp.).
Luxton (1988a) used the smooth notogaster as one of the character states to differentiate Eutegaeoidea from Cepheoidea. No eutegaeoids have a sculptured notogaster, whereas all cepheoids do, except Conoppia Berlese, 1908 and three species of Sphodrocepheus Woolley & Higgins, 1963. Also, most cepheoids have the synapomorphy of a circumnotogastral ring or margin ornamented with different microsculpture from that of the centrodorsal region (present in all species of Cepheus, Hypocepheus, Ommatocepheus, Oribatodes, Tereticepheus; some species of Eupterotegaeus, Sphodrocepheus and Tritegeus; absent in Conoppia, Pilocepheus, Protocepheus, Reticulocepheus and Roycepheus). The structure is similar to that in Scapheremaeus (Cymbaeremaeidae) but with the bases of the notogastral setae or, at most, a groove, rather than a scissure, marking the division between the two contrasting areas of cuticle. In Tritegeus Berlese, 1913, some species of Sphodrocepheus and Hypocepheus Krivolutsky, in Krivolutsky and Tarba, 1971, this margin is positioned more medially and aligned with the bases of setae of the l and h series (cf. Bernini and Bernini, 1990, Figs. 12 and 16; Woolley and Higgins, 1963, Fig. 1; Krivolutsky and Tarba, 1971, Fig. 1). The circumnotogastral margin tends to be flattened (except in Tritegeus spp.) and the centrodorsal region is flat or slightly convex (Bernini and Bernini, 1990, Fig. 1A therein), whereas in Eutegaeoidea the notogaster is strongly and uniformly convex, except in Porrhotegaeus where it is concave with raised margins.
Luxton (1988a) stated that the notogaster of Cepheoidea is at least twice as long as the prodorsum and in Eutegaeoidea it is markedly less so. The mean ratio of the length of the notogaster to the prodorsum in Cepheoidea (n = 54 spp.) is 2.95 (range: 1.72–5.1) and for Eutegaeoidea (n = 80 spp., not including Hamotegeus spp.) 1.62 (range: 1.1–1.97). Hamotegeus spp. are the only Eutegaeoidea that markedly exceed the 2:1 ratio, with a mean of 2.27; range 1.98–2.57. The ratio of notogastral length to breadth in Eutegaeoidea is 0.82 (range 0.71–1) and in Cepheoidea 1.06 (range 0.92–1.27).
As well as the distinctly different biogeographical distribution of Eutegaeoidea and Cepheoidea (Fig. 1), the dorsosejugal scissure in eutegaeoids is transverse and straight (except in some species of Hamotegeus), whereas in cepheoids it is convex and rounded. Humeral processes in Eutegaeoidea are typically long, well-developed and pointed or rounded (except in Cerocepheidae), whereas in Cepheoidea they are small, short, ledge-shaped structures or absent. Other character states occur in a rather matrix-like pattern. For example, the bothridia of Eutegaeoidea are either prominent, long, curved and corniculate, separate anteriorly from the margin of the lamella or, as in Compactozetidae, large, but fused with the lamellae. In Cepheoidea, the bothridia tend to be short and squat, except in Eupterotegaeus where they are long and corniculate in some species. Bothridial setae of Eutegaeoidea tend to be long, thin and setiform or bacilliform and those of Cepheoidea are short and club-shaped, though in Eupterotegaeus they tend to be long and club-shaped. In Eutegaeoidea, the lamellae are generally parallel (except in Sadocepheus) and the lamellar cusp is free and with the lamellar seta emerging from an indentation flanked laterally by teeth or, as in Pterozetidae and some Compactozetidae, the apices of the lamellae are fused. In Cepheoidea, the lamellae are strongly convergent apically (except in Eupterotegaeus and Ommatocepheus) and the free lamellar cusp is typically triangular with the lamellar seta emerging from its apex, not flanked by teeth, except in Eupterotegaeus and Ommatocepheus where the lamellar cusps are curved and the lamellar setae emerge sub-apically.
description: Published as part of 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, pp. 1-93 in Zootaxa 5365 (1) on pages 10-12, DOI: 10.11646/zootaxa.5365.1.1, http://zenodo.org/record/10146969