Megalanceoloides, Zeidler, 2009

Zeidler, Wolfgang, 2009, A review of the hyperiidean amphipod superfamily Lanceoloidea Bowman & Gruner, 1973 (Crustacea: Amphipoda: Hyperiidea), Zootaxa 2000, pp. 1-117 : 78-79

Genus Megalanceoloides gen. nov.

Type species. Lanceola remipes Barnard, 1932 , designated here. The unique type, a female measuring about 40 mm, is in the BMNH (1936.11.2.2510), in spirit. The type locality is the south-west Atlantic [41°43’S 42°20’W]; Discovery Stn. 72, 2000 (-0) m, 1 Jun. 1926.

Diagnosis. Body length about 40 mm or more. Pereon relatively slender, not broadened or curled. Eyes relatively large, kidney shaped. Antennae 1 with large callynophore; terminal three articles subequal in length. Antennae 2 relatively strong; much longer than A1. Mandibles with massive palp; length about 1.5x mandibular body; third article of palp as long, or slightly longer than, first two articles combined; mandibular body relatively narrow above insertion of palp. Maxillae 1; palp with feathered setae on outer distal corner; inner lobes narrow. Maxillae 2; outer lobe armed with four (?) long setae terminally; inner lobe with three (?) long setae. Maxilliped with relatively elongate inner lobes, almost as long as outer lobes. Pereopods 3–7 with very small, retractile dactylus. Pereopods 3–5 with very broad merus, carpus and propodus. Pereopods 5–7 without spoon-shaped process typical of lanceolids.

Monospecific

Sexual dimorphism. Not known due to lack of material but is likely to be similar to that found in Megalanceola except that the pereon is not particularly inflated in females (note type) .

Remarks. This is a very distinctive genus, readily distinguished by the broad articles of pereopods 3–5, the small retractile dactyls of pereopods 3–7 and the highly sculptured cuticle. It is most like Megalanceola in the structure of the mouthparts and antennae. Also, the basis of pereopods 6 & 7 are abruptly narrowed proximally with a small anterior hump, similar to that found on all the pereopods in Megalanceola .

The dactyls of pereopods 3–5 do not seem to be retracted in a spoon-shaped formation, so characteristic of other lanceolids, but rather there is a hollow, fringed with setae, distally on the propodus, into which the dactylus is retracted. In this respect it is similar to Prolanceola but only for pereopods 6 & 7. It is also similar to Prolanceola and Archaeoscinidae in that the third article of the mandibular palp is as long or longer than the first two combined, but differs in most other respects.