Austronanus

Just, Jean & Wilson, George D. F., 2006, Revision of Southern Hemisphere Austronanus Hodgson, 1910, with two new genera and five new species of Paramunnidae (Crustacea: Isopoda: Asellota), Zootaxa 1111, pp. 21-58 : 25-26

Key to genera and species of the Austronanus complex

1. Pleotelson tapering, lateral margins smooth ............................... Xigonus patagoniensis

– Pleotelson rounded with denticles on part of or entire lateral margins......................... 2

2. Frontal margin of head evenly convex; pleotelson proximal margins equal length of lateral margins; denticles on rounded lateral corner only Stephenseniellus gen. nov... 3

– Frontal margin of head forming rounded or pointed angle; pleotelson proximal mar­

gins distinctly shorter than lateral margins; entire lateral margins denticulate .............. .............................................................................................................. Austronanus ... 4 3. Antenna article 3 lateral margin with acute forward pointing denticles; uropods not covered by cuticular hood ............................... Stephenseniellus serraticornis , sp. nov.

– At least part of lateral margin of antenna article 3 with irregular crenate flange; uropods inserted under cuticular hood.................... Stephenseniellus palliolatipes sp. nov.

4. Antennulae with 5 articles, article 5 elongate ............................................................... 5

– Antennulae with 6 articles, article 5 subequal to 4 and 6.............................................. 6

5. Front margin of head with pointed angular apex, lateral margins evenly convex; coxae V–VII with large lateral projection .............................................. Austronanus dentatus

– Front margin of head with rounded apex, lateral margins convex in middle, concave either side; coxae V–VII non­projecting rings, 7 with lateral spine .............................. ............................................................................... Austronanus aucklandensis sp. nov.

6 Frontal margin of head adjacent to apex evenly convex, not sinuous........................... 7

– Frontal margin of head adjacent to apex concave, sinuous.......................................... 8

7. Coxae V–VII with denticles on lateral margin. Pleotelson laterally rounded................. ......................................................................................................... Austronanus dubius

– Coxae V and VI smooth, VII with single lateral denticle. Pleotelson laterally angular anteriorly, straight sided more posteriorly ......................... Austronanus gelidus sp. nov.

8. Antenna article 3 slightly widening distally, with crenate flange on straight lateral and medial margins; flagellum article 1 as long as 2 and half of 3 combined. Pleotelson posterior projection with row of 4 or 5 denticles either side...... Austronanus glacialis .

– Antenna article 3 inflated midlength, margins curved, with crenate flange on lateral margin; flagellum article 1 as long as 2–4 combined. Pleotelson posterior projection with single proximal denticle either side ....................... Austronanus mawsoni sp. nov.