Tmetonyx Stebbing 1906

• Main Authors: Lowry, J. K., Kilgallen, N. M.
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2014
• Subjects: Biodiversity; Taxonomy; Animalia; Arthropoda; Malacostraca; Amphipoda; Uristidae; Tmetonyx; North Atlantic
• Online Access: https://doi.org/10.5281/zenodo.6319065; http://treatment.plazi.org/id/03AE8B60AC4BFF976CC1F96EFBD8C151

Tmetonyx Stebbing 1906 (Fig. 48) Hoplonyx Sars, 1891: 91 (homonym, Coleoptera).— Stebbing, 1894: 9. Tmetonyx Stebbing 1906: 73 (new name).—J.L. Barnard, 1969: 365.— Barnard & Karaman, 1991: 441 (key), 535. Type species. Oniscus cicada O. Fabricius, 1780, original designation. Included species. Tmetonyx includes 8 species: T. acuta (G.O. Sars, 1891); T. albida (G.O. Sars, 1891); T. cicada (O. Fabricius, 1780); T. gulosa (Krøyer, 1845); T. leucophthalma (G.O. Sars, 1891); T. nardonis (Heller, 1867); T. palpiserrata Bellan-Santini, 1985; T. rotundata (Chevreux, 1926a); T. similis (G.O. Sars, 1891). Diagnostic description. Antenna 1 peduncle article 1 without anterodistal lobe; accessory flagellum with an elongate article 1 (at least twice as long as article 2) partially covering callynophore. Antenna 2 with weakly developed brush setae. Mandible molar a reduced column with convex, fully triturating surface. Maxilla 1 outer plate a well developed 7/4 crown. Maxilla 2 inner plate significantly shorter than outer plate. Gnathopod 1 subchelate coxa 1 large, about as long as coxa 2, subrectangular with straight anterior margin ischium long (length 2 × to 4 × breadth) carpus long (length 2 to 4 × breadth) propodus margins subparallel. Uropod 2 inner ramus not constricted . Telson deeply cleft. Remarks. Based on the subchelate gnathopod 1 with a fully developed coxa and long carpus Tmetonyx appears to be similar to Anonyx and Caeconyx . Tmetonyx differs from Anonyx in the accessory flagellum cap (present in Anonyx and Caeconyx ), the mandibular molar (setose with a vestigial triturating surface in Anonyx and Caeconyx ), gnathopod 1 ischium (short in Anonyx and Caeconyx ). Distribution. Atlantic Ocean: North Atlantic; North Polar Sea; Mediterranean Sea. Published as part of Lowry, J. K. & Kilgallen, N. M., 2014, A generic review of the lysianassoid family Uristidae and descriptions of new taxa from Australian waters (Crustacea, Amphipoda, Uristidae), pp. 1-92 in Zootaxa 3867 (1) on pages 78-80, ...