Scleropactes (Schmalfuss, 1980)

Schmidt, Christian, 2007, Revision of the Neotropical Scleropactidae (Crustacea: Oniscidea), Zoological Journal of the Linnean Society 151, pp. 1-339 : 40-41

SCLEROPACTES BUDDE- LUND, 1885

Type species: Scleropactes concinnus Budde-Lund, 1885 [designated by Mulaik (1960)].

Diagnosis

Cephalothorax with frontal shield, behind frontal line with transverse furrow that laterally is recurved and ending medially to the eyes. Mandible with right one/left two penicils on the hairy lobe, and one penicil between the lobe and the pars molaris, which is represented by a tuft of hairy setae. First maxilla with two laterally flattened penicils on the median endite, lateral endite with four plus six teeth, an additional tooth, and a cuticular stalk with a hirsute apex on the rostral surface (cf. Ferrara et al. 1995). Second maxilla with fine setation on the mesal and lateral lobe, both lobes subequal in length. Mesal lobe with a field of sensilla. Maxilliped with a large or vestigial penicil on the frontal face of the endite. Maxilliped palp with one large and one somewhat smaller seta on the basal joint, and the distal tuft of setae on the medial article on a socket. Second and distal article weakly delimited. Carpus of first pereiopod with a welldeveloped antenna-grooming brush in both sexes. Males with brush-like fields of scales, at least the merus and carpus of pereiopods 1 and 2. Exopodites of first two pairs of pleopods have a respiratory area, delimited mesally by a sulcus (no respiratory field visible in Scleropactes pululahua ). Male endopodite 2 slender and straight. Protopodites of uropods filling the gap between pleotelson and epimera of pleonites. Endopodite inserted on the inner edge of protopodite, which is dorsoventrally flattened [based on the definition given by Leistikow (1997)].

Remark

Vandel (1972) enumerated several characters that Scleropactes has in common with the Scyphacidae (first antenna with aesthetascs in several rows, second antenna with three-jointed flagellum, maxilliped endite with penicil, ‘well-developed’ dactylar seta, pleopod exopodites with haemolymph sinus). All these are plesiomorphies, and after Vandel they prove that Scleropactes is the most primitive genus of the Scleropactidae . Schultz (1995) erroneously mentioned that the flagellum of the second antenna of Scleropactes has two joints.

The mention of Scleropactes concinnus as ‘genotipo’ of Scleropactes by Mulaik (1960) is regarded as the designation of the type species, according to ICZN Art. 69 a iii.

At present, the genus Scleropactes is probably still paraphyletic. The present analysis revealed only very weak characters as putative apomorphies.