Morphogenia, Parker, Joseph, 2014

Parker, Joseph, 2014, Morphogenia: a new genus of the Neotropical tribe Jubini (Coleoptera, Staphylinidae, Pselaphinae) from the Brazilian Amazon, ZooKeys 373, pp. 57-66 : 58-59

Morphogenia gen. n.

Type species.

Morphogenia struhli , here designated.

Diagnosis.

Morphogenia , and its only species, Morphogenia struhli , can be distinguished from all other known jubine genera by the following combination of characters: (1) smoothly convex vertex lacking sulci, and afoveate due to anterolateral shift of vertexal foveae into vicinity of postantennal notches anterior to eyes; (2) absence of V- or Y-shaped gular carina; (3) pronotum with margins smooth, lacking lateral spines, and with a simple, well-defined transverse antebasal sulcus in both sexes; (4) abdomen lacking fovea-like cuticular pockets at bases of tergites V–VII and sternites V–VII (but tergite IV and sternite IV with true mediobasal foveae present).

Description.

Body length ~3 mm (Fig. 1). Form relatively flattened and broadened posteriorly, with compact abdomen and elongate legs.

Head: Approximately triangular (Figs 1, 18), 1.3 × wider than long; without distinct frontal rostrum and lacking prominent, raised antennal tubercles. Vertex smoothly convex, devoid of foveae or sulci, lateral margins incised behind antennal sockets by postantennal notches (region enclosed by dashed line in Fig. 2). Antennae separated by 1/3 maximum head width. Foveae of apparent homology to the vertexal foveae of other Pselaphinae shifted from vertex, situated instead on frontolateral margins, recessed into the top of postantennal notches (Figs 2, 5). Apodemes of tentorium extending from these foveae (Fig. 5) and converging on gular foveae with single opening (Fig. 3). Lateral margins of head smoothly rounded dorsoventrally, lacking ocular mandibular carina. Venter lacking any trace of gular carina (Fig. 3; a medial sutural line can be weakly detected). Antennae (Fig. 4) with 11 antennomeres, with club formed by enlarged antennomeres VIII–XI. Maxillary palpi comprised of five palpomeres, with small triangular palpomeres III and fusiform palpomeres IV (Fig. 3). Maxillary cardos projecting anteriorly, reaching slightly beyond sides of mandibles, with single long setae positioned at apex.

Thorax: Pronotum (Fig. 6) moderately transverse, 1.4 × wider than head and similar in length, obcordate in shape, approximately semicircular before abrupt constriction in basal quarter. Lateral margins before constriction smoothly rounded, without spines or teeth. Pronotal disc simple and convex, lacking foveae or sulci. Typical, deep and well-impressed antebasal sulcus present, demarcating point of pronotal constriction. Lateral antebasal foveae present, median antebasal fovea absent. Prosternum with lateral procoxal foveae. Mesoventrite with single unpaired median mesoventral fovea, lateral mesoventral foveae and lateral mesocoxal foveae. Metaventrite with lateral metaventral foveae, with median carina from 1/3 segment length to posterior margin.

Abdomen: Abdomen 2/3 length of elytra (measured along suture). Five tergites ( IV–VIII) evident. Tergites with broad, angularly-projecting paratergites on segments III–VI and smaller paratergites on VII (Fig. 7). Tergite IV longest, 2.7 × tergite V length, with posterior tergites becoming shorter and narrower. Tergite IV with mediobasal foveae present in basal sulcus. Six sternites ( III–VIII) evident; penial plate apparently internalized, not externally visible, with genital aperture formed by contiguous apical margins of tergite and sternite VIII (Figs 11, 12). Apical margin of sternite III entire, uninterrupted by metacoxae. Sternite IV longest, mediobasal foveae present. All tergites and sternites lacking fovea-like cuticular pockets at their bases (Fig. 7 shows bases of tergites V–VII revealed in cleared specimen).

Elytra: 1.3 × longer than pronotum, broadening gradually until narrowing just before apices. With sinuate transverse basal carina; sutural foveae and single median basal foveae present but largely obscured by arcing of basal carina. Humeri indented by impressed bases of humeral sulci; humeral sulci extending length of elytra, with humeral foveae at base. Sutural striae entire.

Legs: All pairs of coxae contiguous. Coxae all carinate along length of external face. Procoxal length greater than half femoral length, procoxae strongly conically projecting ventrally. Mesocoxae shorter than procoxae, moderately conically projecting, orientated somewhat posteriorly. Metacoxae transverse-conical, spanning from ventral midline to metaventral margin, and projecting posteriorly. All trochanters short, with negligible separation of coxal apex and femoral base ( “brachysceline” type). Femora and tibiae simple, lacking modifications. Profemora somewhat thickened. Tarsi (Figs 8, 9) 3-segmented with short tarsomeres I; tarsomeres II longest. Metatarsi especially elongate. Tarsi with two claws of equal size.

Etymology.

Morphogens are gradient-forming molecules that specify positional information and govern tissue growth during animal development. The generic name acknowledges the pervasive role of morphogens in sculpting organismal morphology. The gender is feminine.