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| Format: | Recurso digital |
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Zenodo
2020
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| Online Access: | https://doi.org/10.5281/zenodo.6422236 |
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Table of Contents:
- <p><b><i>Ammonixys</i> gen. nov.</b></p><p><b>Diagnosis</b>. Body globular with swollen, almost spherical, fourthpedigerous somite. Freeurosome 5-segmented. Caudalsetae obscure. Rostrum well-developed.Antennule small, 6-segmented. Antenna 4-segmented withsmall terminal claw. Mandible with 4 teeth on coxal gnathobase; exopod fused with basis, represented by 2 setae; endopod 2-segmented with 1 and 4 setae on first and second segments, respectively. Maxillulewith 6 setaeon arthrite, 1 each on coxal epipodite and basis, 4 on exopod and 3 on endopod; coxal endite absent. Maxilla 4-segmented; syncoxa with 2 endites; basis with claw plus 1 seta; endopod 2-segmented. Maxilliped as unsegmented lobe bearing 4 setae. Legs 1–3 with 3-segmented rami. Leg 4 with 3-segmented exopod and 2-segmented endopod. Innercoxalsetaabsentinlegs 1–4. Leg 1 lacking inner distal element on basis. First and second exopodal segments of legs 1–4 lacking inner seta. First and second endopodal segments of legs 1–3 lacking inner seta. Leg 5 represented by lobe and tapering, sclerotized process located ventrodistally on somite.</p><p><b>Typespecies</b>. <i>Ammonixysquadridens</i> <b>gen. etsp. nov.</b> by original designation.</p><p><b>Etymology</b>. The name is derived from the Greek <i>ammon</i> (=African) and <i>ixys</i>, referring to the discovery of the new genus in Africa.</p><p><b>Remarks</b>. <i>Ammonixys</i> <b>gen. nov.</b> resembles <i>Doroixys</i> in the absence of the inner seta on the proximal endopodal segment(s) of legs 2–4, but the new genus exhibits a striking derived feature separating it from <i>Doroixys</i> and other genera, namely, the loss of a distinct mandibular exopod. The exopod is respresented only by a pair of setae originating on the surface of the fused basis plus exopod. The setation of leg 1 is also distinctive because the first and second exopodal and endopodal segments of leg 1 all lack an inner seta, and the basis of leg 1 is unarmed. This setation of leg 1 differs from that expressed by the four new genera described above, <i>Prodoroixys</i> <b>gen. nov.</b>, <i>Notoixys</i> <b>gen. nov.,</b> <i>Borixys</i> <b>gen. nov.</b>, and <i>Cystixys</i> <b>gen. nov.</b> Although the loss of inner setae from the exopod of leg 1 occurs in <i>Loboixys</i>, the latter genus usually retains the inner setae on the endopod of leg 1. Unlike in <i>Ammonixys</i> <b>gen. nov.</b>, the seven known species of <i>Loboixys</i> each have a 3-segmented antenna and carry 6 setae on the maxilliped. This constitutes an additional significant difference between <i>Loboixys</i> and <i>Ammonixys</i> <b>gen. nov.</b>, which has a 4-segmented antenna and carries only 4 setae on the maxilliped.</p>