Thorkelius, Bird, Graham, 2004

Bird, Graham, 2004, Tanaidacea (Crustacea) of the Northeast Atlantic: non­filiform species of Anarthruridae Lang from the Atlantic Margin, Zootaxa 471, pp. 1-44 : 21

Thorkelius gen. nov.

Leptognathia: Hansen, 1913: 101 –102. Leptognathia: Lang, 1968: 159 , table II.

Type species. Leptognathia latiremis Hansen, 1913 .

Diagnosis. Anarthrurid with normally developed pleon. Labrum conical, not laterally compressed. Mandible weak with elongate incisor process, without molar or lacinia mobilis. Maxillule endite with five (or six?) setae. Maxilliped endite with one seta; palp article­ 3 with four large setae. Cheliped propodus without lateral fold; fixed finger with two ventral spiniform setae. Carpus of pereopods 4–6 with three complex spiniform setae and one smaller dorsal seta. Pleopods present.

Etymology. After the Icelandic demon character ‘Thorkel’, from the ‘Tale of Thorstein Shiver’; alluding to its prevalence in the cold, dark depths of the seas north and east of Iceland.

Remarks. An apparently significant discrepancy exists between this diagnosis and the description and drawings of the mouthparts given by Hansen for L. latiremis . He shows large and robust mandibles that possess both a lacinia mobilis and well developed molar, and a maxilliped that has palps relatively small in relation to the bases; the palp article­3 is also depicted with only two inner setae. These all give the impression of belonging to an akanthophoreinid, colletteid or tanaellid rather than an anarthrurid and that a probable lapsus calami has occurred.

Two species are placed in this genus, L. latiremis and L. glacialis . They differ from all known anarthrurids in the possession of four inner setae on maxilliped palp article­3.