Synuropus granulatus, RICHARDSON, 1901

Schmidt, Christian, 2007, Revision of the Neotropical Scleropactidae (Crustacea: Oniscidea), Zoological Journal of the Linnean Society 151, pp. 1-339 : 74-75

SYNUROPUS GRANULATUS RICHARDSON, 1901

Synuropus granulatus – Van Name (1936 *).

Scleropactes grandulatus (misspelling) – Schultz (1970); Schmalfuss (1980).

Scleropactes granulatus – Leistikow & Wägele (1999 *); Schmalfuss (2003 *).

Material examined

Types: One ♀ holotype ( Puerto Rico, El Yunque , altitude 850 m, leg. L. Stejnegen, Type; USNM 23912 ) .

Description ( Fig. 231 )

Female 6.3 × 3.35 mm. Pigment not preserved: ‘brown, mottled with black’ (after Richardson, 1901). Body dorsoventrally flattened, with oval outline, nonconglobating. Cephalothorax with distinct median and lateral lobes. Eyes composed of 19 ommatidia. Tergites shallowly tuberculate. Coxal plate 1 with right-angled hind corners, coxal plates 2–7 with acute angles, the corners pointing backwards. Epimeres of pleon segments 3–5 decreasing in length and width. Pleotelson triangular with rounded tip, slightly projecting beyond the uropod protopodites. Second antenna with three-jointed flagellum. The apical cone exceeds the length of the terminal article. Uropod sympodite massive, not flattened, slightly surpassed by the tip of the pleotelson. Exopodites and endopodite approximately equal-sized, lanceolate, as long as the visible part of the sympodite.

Geographical distribution

Puerto Rico.

Habitat

The specimen was collected at 850 m altitude; no further information on the habitat was given.

Remark

The synonymization of Synuropus with Scleropactes was certainly wrong. Schmalfuss (1980) assumed that ‘ Scleropactes grandulatus ’ does not belong to the Scleropactidae . Synuropus does not even resemble species of Scleropactes very much. Besides the lack of the transverse furrow on the cephalothorax, it is not clear why Synuropus should be a member of the Scleropactidae . The length of the apical cone of the second antennae is similar to that in most of the Scleropactidae and Philosciidae . The flattened body shape is to be considered plesiomorphic with respect to the conglobating Scleropactidae , but apomorphic with respect to the Philosciidae . The shape of the uropod protopodites is also intermediate between Scleropactes and representatives of the Philosciidae . In consequence, Synuropus might be considered as a sister group of the Scleropactidae or of the South American Scleropactidae only.

However, as only the type specimen is known, most phylogenetically important characters, such as mouthparts and pleopods, remain unknown. It is also not certain that the specimen is adult.

Figures

Figure 231. Synuropus granulatus Richardson, 1901: holotype ♀, 6.3 × 3.35 mm (Puerto Rico, El Yunque, altitude 850 m, leg. L. Stejnegen, USNM 23912).