Magnovidae, Alves, Lowry & Johnsson, 2020

Alves, Jessika, Lowry, James K. & Johnsson, Rodrigo, 2020, A new superfamily and family of Hadziida (Amphipoda: Senticaudata), with a description of a new genus and new species from the Brazilian continental shelf, Zootaxa 4779 (4), pp. 573-583 : 574-575

Magnovidae fam. nov.

Diagnosis. With the characters of the superfamily.

Etymology. The family name is based on the type genus Magnovis .

Remarks. The Magnovidae is distinct from all other hadziidan families in having, among other characters, antenna 1 shorter than the peduncle of antenna 2, a molar dominating the mandible and well-developed basofacial setae on the peduncle of uropod 1.

Buccal appendages are morphologically similar to calliopioidean amphipods, such as Membrilopus Barnard & Karaman, 1987 and Regalia K.H. Barnard, 1930 . Moreover, in the Magnovidae fam. nov. the rami of uropod 3 are subequal in length and longer than peduncle, an apomorphic character state of the family Maeridae , but the shape of rami are strongly ovate, with many long marginal setae, a character state which dominates the Hadziida .

Several characteristics such as: (1) pilose antenna 2 cone gland; (2) the presence of slender and long setae on appendages; (3) significant reduction of carpus and propodus in pereopods 3–7; (4) and strong sexual dimorphism are also powerful apomorphies distinguishing the Magnovidae .

Magnovidae is similar to Cheirocratidae and Megaluropidae in that all three families share a very short antenna 1, shorter than the peduncle of antenna 2. But cheirocratids do not have basofacial robust setae on uropod 1. Magnovids do not have dorsal spines on the urosomites. In addition, megaluropids have a normal molar, maxilla 2 with an oblique setal row on the inner plate, and very long seventh pereopods.