taxonID	type	description	language	source
002487F22016FFDBFF142E6BFC18F990.taxon	materials_examined	Material examined. Expedition Maurit 1011: Stn MU 276, Mauritania, off Saint Louis (16 ° 18´56 ″ – 16 ° 21´53 ″ N, 16 ° 53´25 ″ – 16 ° 52´41 ″ W), 637 – 562 m depth, muddy fine sand, commercial trawl, 7. XII. 2010; 1 male TL / CL: 35.46 / 12.67 mm, both right pereiopods 3 and 4 missing. Stn MUDR 09, Mauritania, canyon area off Banc d’Arguin (20 ° 14´36 ″ N, 17 ° 40´10 ″ W), 525 - m depth, muddy coral rubble, rock dredge, 19. XI. 2010; one juvenile TL / CL: 20.14 / 7.39 mm, both pereiopods 1 and 3, and right pereiopod 5 missing. Stn MUDR 10, Mauritania, canyon area off Banc d’Arguin (19 ° 50´01 ″ N, 17 ° 37´03 ″ W), 520 - m depth, mud with coral rubble, rock dredge, 22. XI. 2010; one male TL / CL: 28.28 / 10.27 mm, left pereiopods 1 – 3 missing. Infraorder ‘ Sakai et al. ’ ‘ Dworschak et al. ’ Infraorder families families Thalassinidea Laomediidae Axianassidae 1 Gebiidea Laomediidae Thalassinidae Thalassinidae Upogebiidae Upogebiidae Callianassidea Axiidae Axiidae Axiidea Calocarididae 2 Coralaxiidae 2 Eiconaxiidae 2 Eiconaxiopsididae 2 Anacalliacidae 3 Callianassidae Bathycalliacidae 3 Callianassidae 3 Callianopsidae Eucalliacidae 3 Lipkecallianassidae 3 Callianideidae Callianideidae Thomassiniidae 4 Ctenochelidae Ctenochelidae Ctenocheloidae 5 Gourretiidae 5 Pseudogourretiidae 5 Meticonaxiidae 6 Micheleidae Micheleidae Strahlaxiidae Strahlaxiidae 1. Dworschak et al. (2012) kept this family separate, as originally designated by Schmitt (1924), although its single genus Axianassa was also placed in Laomediidae (Poore 1994, among others). 2. Calocarididae and Eiconaxiidae were subsumed into Axiidea, while Coralaxiidae and Eiconaxiopsididae were not mentioned by Dworschak et al. (2012). Corallaxiidae was erected as an axiid subfamily by Sakai and de Saint Laurent (1989) and subfamilies were not considered in Dworschak et al. (2012). Eiconaxiopsididae was erected by Sakai (2011) to host the new genus Eiconaxiopsis, including the new species E. heinrichi and E. sibogae. Eiconaxiopsis sibogae was previously placed in Eiconaxiidae [as Eiconaxius sibogae (de Man, 1925)]. Notice here that Dworschak et al. (2012) ’ s manuscript was conluded on 5 July 2010, long before Sakai’s work has been published. 3. None of these families were mentioned by Dworschak et al. (2012) and all of them were at first described as callianassid subfamilies (Manning and Felder 1991; Sakai and Türkay 1999; Sakai 2005 a). 4. Thomassiniidae was subsumed into Callianideidae by Dworschak et al. (2012). 5. Pseudogourretiidae was originally described as a subfamily within Gourretiidae (Sakai, 2005), but this family was subsumed into Ctenochelidae by Dworschak et al. (2012). Ctenocheloidae was erected by Sakai (2011: 595) for the single species Ctenocheloides attenboroughi Anker, 2010, which was originally placed in Ctenochelidae. Posteriorly, Komai (2013) described a new Ctenocheloides species, C. nomurai, but the author keep the genus in the family Ctenochelidae. 6. Meticonaxiidae was described as a subfamily under Callianideidae (Sakai, 1992 a) but was later transferred to Micheleidae (Poore, 1994). Infraorder Family Maurit surveys thalassinidean species Family Infraorder (‘ Sakai et al. ’) (‘ Dworschak et al. ’)	en	De Matos-Pita, Susana S., Ramil, Fran (2015): Additions to thalassinidean fauna (Crustacea: Decapoda) off Mauritania (NW Africa) with the description of a new genus and a new species. Zootaxa 4020 (3): 571-587, DOI: 10.11646/zootaxa.4020.3.9
002487F22016FFDBFF142E6BFC18F990.taxon	distribution	Distribution. East Atlantic, from the north of Europe to tropical West Africa (at least to Mauritania; present work, see remarks) and the Mediterranean Sea (Sakai & de Saint Laurent 1989; Ngoc-Ho 2003).	en	De Matos-Pita, Susana S., Ramil, Fran (2015): Additions to thalassinidean fauna (Crustacea: Decapoda) off Mauritania (NW Africa) with the description of a new genus and a new species. Zootaxa 4020 (3): 571-587, DOI: 10.11646/zootaxa.4020.3.9
002487F22016FFDBFF142E6BFC18F990.taxon	discussion	Remarks. Calocarides coronatus has been found evenly distributed in the north of Europe (Norway, Sweden, Denmark, North Sea) but is not reported from the British Isles (Ngoc-Ho 2003). The same author corroborated the inclusion in this species of the small Mediterranean specimens reported by Cartes et al. (1994, Catalan Sea) and García Raso (1996, Alboran Sea), and also noted that the species was not recorded from South European Atlantic coasts. Ngoc-Ho (2003) also considered as doubtful the assignment to C. coronatus (for ‛ geographical reasons’, Sakai and de Saint Laurent, 1989: 79) of the material previously identified as Calocarides longispinis (McArdle, 1901) by Stebbing (1910: 368; as Calastacus longispinis) from South Africa and by Macpherson (1983: 45, as Calastacus longispinis; in part, see below) from Namibia. Material from Table Mountain named as Calastacus longispinis [not C. longispinis McArdle, 1901 = Calocarides longispinis (McArdle, 1901)] by Stebbing (1910: 368), reported and figured later by Barnard [1950: 503, fig. 93 d-f; as Calocaris (Calastacus) longispinis] and also listed by Kensley (1981: 30; as Calocaris longispinis), was described as the new species Calocarides capensis by Kensley (1996). Namibian material (20 ° – 21 ° S) identified as Calastacus longispinis by Macpherson (1983: 45) was also described as the new species Calocarides macphersoni by Kensley (1996). Material sampled in South Namibia [26 ° S; Macpherson 1983: 45 as Calastacus longispinis (McArdle, 1901)], and included in Calocarides coronatus by Sakai & de Saint Laurent (1989: 80), was subsequently transferred to Calocarides capensis by Sakai (2011: 88).	en	De Matos-Pita, Susana S., Ramil, Fran (2015): Additions to thalassinidean fauna (Crustacea: Decapoda) off Mauritania (NW Africa) with the description of a new genus and a new species. Zootaxa 4020 (3): 571-587, DOI: 10.11646/zootaxa.4020.3.9
002487F22010FFDAFF142F2FFBD9FAB2.taxon	materials_examined	Material examined. Expedition Maurit 0911: Stn. MUDR 06, off Mauritania (17 ° 40´22 ″ N, 16 ° 40´11 ″ W) on coldwater coral reef, 435 - m depth, mud with coral rubble, rock dredge, 10. XII. 2009; two hermaphrodites, TL / CL: 28.46 / 10.08 mm (both pereiopod 1, left pereiopod 3 and right pereiopod 4 missing) and TL / CL: + 23.86 / + 10.25 mm (half rostrum, all pereiopods missing, abdomen detached). Expedition Maurit 1011: Stn. MUDR 11, canyon area off Banc d’Arguin, Mauritania (19 ° 38´25 ″ N, 17 ° 06´52 ″ W), 322 - m depth, rock, rock dredge, 26. XI. 2010; one hermaphrodite, TL / CL: 26.38 / 9.46 mm, both pereiopod 1, left pereiopod 3 and right pereiopod 4 missing. Stn. MUDR 12, canyon area off Banc d’Arguin, Mauritania (19 ° 52´38 ″ N, 17 ° 22´23 ″ W), 485 - m depth, muddy coral rubble and shell debris, rock dredge, 26. XI. 2010; four hermaphrodites, TL / CL: + 31.02 / + 9.84 mm (rostrum and left pereiopods 2 and 5 missing, telson damaged), TL / CL: 14.56 / 8.99 mm (right pereiopod 1, pereiopod 4 and pereiopod 5 missing), TL / CL: 34.06 / 12.35 mm (ovigerous; both pereiopod 1 missing) and TL / CL: 32.62 / 11.95 mm (ovigerous; left pereiopods 1, 3 and 4, and right pereiopod 4 missing, carapace and left uropod damaged). Stn. MUDR 16, canyon area off Banc d’Arguin, Mauritania (19 ° 30´59 ″ N, 17 ° 05´54 ″ W), 474 - m depth, muddy coral rubble and shell debris, rock dredge, 27. XI. 2010; two hermaphrodites, TL / CL: 24.18 / 8.50 mm (left pereiopod 3 and right pereiopod 1 missing) and TL / CL: 27.43 / 9.97 mm (left pereiopods 3 and 4, and right pereiopods 1, 4 and 5 missing, left pereiopod 1 detached). Stn. MUDR 21, off Mauritania (16 ° 28´13 ″ N, 16 ° 51´43 ″ W) on cold-water coral reef, 522 - m depth, muddy coral rubble, rock dredge, 9. XII. 2010; one hermaphrodite, TL / CL: 28.41 / 11.14 mm (left pereiopods 3, 4 and 5, and right, pereiopod 3 missing). Stn. MUDR 22, off Mauritania (16 ° 47´30 ″ N, 16 ° 50´28 ″ W) on cold-water coral reef, 460 - m depth, muddy coral rubble, rock dredge, 9. XII. 2010; three hermaphrodites, TL / CL: 28.86 / 10.88 mm (all pereiopods missing except right pereiopod 1, abdomen damaged), TL / CL: + 24.68 / + 8.67 mm (half rostrum, all pereiopods missing except right pereiopods 2 and 5, specimen broken in two fragments) and TL / CL: 39.45 / 10.46 mm (ovigerous, left pereiopods 2 – 4 and right pereiopods 1 – 4 missing. Habitat. This species has been reported on bottoms of shell debris (García Raso 1996), mud, mud with amphipod tubes, bioturbated mud, mud with cold-water coral debris (mainly Lophelia pertusa and Madrepora oculata) (d’Udekem d’Acoz 1999; Sakai et al. 2015), at depths of 13 to 1432 m (Dworschak 2000). Our specimens were all captured in muddy coral rubble, at depths between 322 and 522 m.	en	De Matos-Pita, Susana S., Ramil, Fran (2015): Additions to thalassinidean fauna (Crustacea: Decapoda) off Mauritania (NW Africa) with the description of a new genus and a new species. Zootaxa 4020 (3): 571-587, DOI: 10.11646/zootaxa.4020.3.9
002487F22010FFDAFF142F2FFBD9FAB2.taxon	distribution	Distribution. East Atlantic from Iceland and Norway southwards to South Africa, including Mediterranean Sea (Ngoc-Ho 2003; Sakai 2011). Previously reported from Mauritanian waters by Sakai & de Saint Laurent (1989) and Sakai et al. (2015).	en	De Matos-Pita, Susana S., Ramil, Fran (2015): Additions to thalassinidean fauna (Crustacea: Decapoda) off Mauritania (NW Africa) with the description of a new genus and a new species. Zootaxa 4020 (3): 571-587, DOI: 10.11646/zootaxa.4020.3.9
002487F22010FFDAFF142F2FFBD9FAB2.taxon	discussion	Remarks. This species has been reported off Mauritania at 587 to 600 m (Sakai & de Saint Laurent 1989) and between 483 and 545 m (Sakai et al. 2015), which concurs with our findings. Along the West African coast, this species has also been reported slightly deeper at 719 – 724 - m depth off Morocco (García Raso 1996), at 300 and 380 - m depth off Namibia (Macpherson 1983 as Calocaris barnardi) and shallower at 84 and 162 - m depth off the South African Atlantic coast (Barnard 1950 as Calocaris (Calocaris) barnardi).	en	De Matos-Pita, Susana S., Ramil, Fran (2015): Additions to thalassinidean fauna (Crustacea: Decapoda) off Mauritania (NW Africa) with the description of a new genus and a new species. Zootaxa 4020 (3): 571-587, DOI: 10.11646/zootaxa.4020.3.9
002487F22011FFD8FF142DC3FADCFD2B.taxon	materials_examined	Material examined. Expedition Maurit 0911: Stn. MU 215, off S Nouakchott (Mauritania) (17 ° 29´44 ″ – 17 ° 28´06 ″ N; 16 ° 39´31 ″ – 16 ° 40´10 ″ W), 358 – 364 - m depth, muddy fine sand, commercial trawl, 2. II. 2009; one male TL / CL: 19.09 / 4.52 mm, both pereiopods 1 missing, left P 4 merus to dactylus detached and both pleopods 3 missing. Expedition Maurit 1011: Stn. MUDR 26, off S Nouakchott (Mauritania) cold-water coral reef (17 ° 29´42 ″ N, 16 ° 41´04 ″ W), 441 - m depth, mud with coral rubble and shell debris, rock dredge, 12. XII. 2010; one incomplete female, TL / CL: + 12.23 / 4.94 mm, right pereiopod 1 carpus and chela, both pereiopods 3 – 5, abdominal segments 3 – 5 and telson are all missing.	en	De Matos-Pita, Susana S., Ramil, Fran (2015): Additions to thalassinidean fauna (Crustacea: Decapoda) off Mauritania (NW Africa) with the description of a new genus and a new species. Zootaxa 4020 (3): 571-587, DOI: 10.11646/zootaxa.4020.3.9
002487F22011FFD8FF142DC3FADCFD2B.taxon	description	Description. Our male specimen mostly corresponds to the type description provided by Le Loeuff & Intès (1974). Both specimens present a rudimentary, uniramous and bisegmented pleopod 1 (as shown in Le Loeuff & Intès 1974: fig. 9 r). While the type specimen was described with pleopods 2 – 5 missing, in our male specimen, although no scar or trace of pleopods can be appreciated on pleomere 2, a conspicuous scar is present in place of pleopod 3; pleopods 4 and 5 are biramous and foliaceous (Fig. 2 A), with an appendix interna projecting from the distal proximal third of the endopod inner border, and with distal margin obliquely truncate and furnished with hooks (Figs. 2 A, B). Our incomplete female specimen also corresponds to the original description. Differences observed are those referring to the sex: conspicuous gonopore on both pereiopod 3 coxa, pleopod 1 uniramous and bisegmented (Fig. 2 C), and pleopod 2 slender, biramous, with endopod bearing a terminal appendix interna (Fig. 2 D). Habitat. The type specimen was collected at 200 m with a DRB: drague à dents (72 × 30 cm); no bottom was specified (Le Loeuff & Intès 1974). Our specimens were captured off South Nouakchott, at two geographically close stations, on muddy fine sand and muddy coral rubble, at depths between 358 – 364 and 441 m.	en	De Matos-Pita, Susana S., Ramil, Fran (2015): Additions to thalassinidean fauna (Crustacea: Decapoda) off Mauritania (NW Africa) with the description of a new genus and a new species. Zootaxa 4020 (3): 571-587, DOI: 10.11646/zootaxa.4020.3.9
002487F22011FFD8FF142DC3FADCFD2B.taxon	distribution	Distribution. Previously reported only from the type locality (Ivory Coast) and now from Mauritania, this species seems to be restricted to the West African tropical region.	en	De Matos-Pita, Susana S., Ramil, Fran (2015): Additions to thalassinidean fauna (Crustacea: Decapoda) off Mauritania (NW Africa) with the description of a new genus and a new species. Zootaxa 4020 (3): 571-587, DOI: 10.11646/zootaxa.4020.3.9
002487F22011FFD8FF142DC3FADCFD2B.taxon	discussion	Remarks. To date, the type specimen (male CL: 3.5 mm) from Ivory Coast (200 m) is the only one ever recorded. After its original description as Callianassa oblonga, the species was included in the genus Cheramus Bate, 1888 as C. oblongus by Manning & Felder (1991), and accepted by Tudge et al. (2000) in this genus. However, Sakai (2005: 20) was unable to find enough morphological characters that reliably separated both genera; he therefore synonymized the genus Cheramus with Callianassa. On the other hand, a tendency to group Callianassa species based on pleopod morphology, among other characters, led Saint Laurent and Le Loeuff (1979: 55) to recognize three groups: one including species with pleopod 1, but not pleopod 2; a second group of species lacking either pleopod 1 or pleopod 2; and a third group with ‛ des pléopodes présents, bien que faiblement développés, sur les deux premiers segments abdominaux du mâle’ (pleopods on male absominal segments 1 and 2 present, although reduced). These authors included only one species, Callianassa oblonga, in the last group, although this species was originally described as with ‛ pléopode 1 réduit, en forme de doigt de gant à extrémité courbe; les autres pléopodes manquent. ’ (pleopod 1 reduced, fingerlike and with tip curved; pleopods 2 – 5 absent) (Le Loeuff and Intès 1974: 40); however, although a reduced pleopod 1 is present (and bisegmented as shown in Le Loeuff and Intès (1974): fig. 9 r), there is no clear evidence of an existing pleopod 2. In his synopsis of the family Callianassidae, Sakai (1999) first associated C. oblonga with Callianassa species without pleopod 2 (Sakai 1999: 5). However, in his account of the species (Sakai 1999: 18), he described it as having male pleopods 1 and 2, as did Saint Laurent and Le Loeuff (1979). Some years later, with the revision of the Callianassoidea of the world, Sakai (2005 a) arranged the Callianassa species into four groups according to the morphology of pleopods l and 2, including C. oblonga within the group with uniramous and two-segmented pleopod l, and with pleopod 2 absent (Sakai 2005: 25, 32). The same author (Sakai 2011: 355) later considered the morphology of male pleopods 1 and 2 as the single valid character for callianassid genera classification, redescribing, among others, the genera Callianassa (to include species with male pleopod 1 uniramous and bisegmented, and with male pleopod 2 uniramous, in which the protopod rarely protruded short distolaterally), Trypaea (male pleopod 1 uniramous, uni-, bi- or trisegmented, and male pleopod 2 absent), and Cheramus (male pleopod 1 absent, or uniramous and bisegmented, and with slender, biramous male pleopod 2), and subsequently, returning Callianassa oblonga to the genus Cheramus (as Cheramus oblongus). All the foregoing propositions of classification were based on pleopod morphology. However, neither of the only two males ever recorded (the type specimen and the one captured during the Maurit surveys) displayed pleopod 2, and there is no evidence of their existence (at least in our material). In consequence, we propose here the relocation of C. oblonga to the genus Trypaea as Trypaea oblonga (Le Loeuff & Intès, 1974) n. comb.	en	De Matos-Pita, Susana S., Ramil, Fran (2015): Additions to thalassinidean fauna (Crustacea: Decapoda) off Mauritania (NW Africa) with the description of a new genus and a new species. Zootaxa 4020 (3): 571-587, DOI: 10.11646/zootaxa.4020.3.9
002487F22013FFD7FF142B0EFCDEFBBE.taxon	diagnosis	Diagnosis. Carapace faintly pitted. Rostrum triangular with upturned tip, laterally spinose, extending posteriorly as lateral carinae. Gastric region elevated, bearing 5 carinae: median, submedian and short lateral; submedian carinae converging anteriorly to form a horseshoe-like shape. No linea thalassinica. Cervical groove distinct only on dorsal surface, postcervical carina wide and short, weakly visible only over posterior median lobe. Eyes short, unpigmented, one-third rostrum length. Antennal acicle elongate, protruding straight forward. Anterolateral margin broadly rounded, unarmed. Maxilla 2 exopod posterior lobe with one long seta. Maxillipeds 1 – 3 with exopod and single epipod; maxilliped 2 with single podobranchia; maxilliped 3 with double podobranchia and single arthrobranchia. Pereiopods 1 and 2 chelate, pereiopods 1 – 4 with single epipod and double arthrobranchia, pereiopods 1 – 3 with double podobranchia. Pleurobranchia absent. Pleomeres unarmed; first somite with pleura acute; second broad, anteriorly and posteriorly rounded; 3 – 5 anteriorly rounded, declining to a rounded angle posteriorly; pleura on somite 6 rounded. Pleopod 1 uniramous, unsegmented; pleopods 2 – 5 alike, slender, with appendix interna; pleopod 2 without appendix masculina. Uropod exopod with spinose transverse suture. Telson longer than wide, with posterior margin rounded, without posteromedian tooth. Hermaphrodite.	en	De Matos-Pita, Susana S., Ramil, Fran (2015): Additions to thalassinidean fauna (Crustacea: Decapoda) off Mauritania (NW Africa) with the description of a new genus and a new species. Zootaxa 4020 (3): 571-587, DOI: 10.11646/zootaxa.4020.3.9
002487F22013FFD7FF142B0EFCDEFBBE.taxon	materials_examined	Type species. Ezaxius ferachevali new species, by present designation.	en	De Matos-Pita, Susana S., Ramil, Fran (2015): Additions to thalassinidean fauna (Crustacea: Decapoda) off Mauritania (NW Africa) with the description of a new genus and a new species. Zootaxa 4020 (3): 571-587, DOI: 10.11646/zootaxa.4020.3.9
002487F22013FFD7FF142B0EFCDEFBBE.taxon	etymology	Etymology. Generic name is a combination of the name Eza from the Spanish R / V Vizconde de Eza, on which the Maurit surveys were conducted, and the genus name Axius. Gender masculine.	en	De Matos-Pita, Susana S., Ramil, Fran (2015): Additions to thalassinidean fauna (Crustacea: Decapoda) off Mauritania (NW Africa) with the description of a new genus and a new species. Zootaxa 4020 (3): 571-587, DOI: 10.11646/zootaxa.4020.3.9
002487F22013FFD7FF142B0EFCDEFBBE.taxon	discussion	Remarks. Ezaxius n. gen., described here with pereiopod 2 chelate, should be included in the infraorder Axiidea / Callianassidea (see Table 1). Within this infraorder, the following combination of characters separates the new genus from all except the Axiidae and related families (see Table 1): the absence of linea thalassinica, the presence of a conspicuous rostrum and the presence of a long seta on maxilla 2 exopod posterior lobe. The presence of a uropodal exopod transverse suture, epipods on pereiopods 1 – 4 and an appendix masculina attached mesially on pleopod 2 endopod exclude the new genus from ‘ Sakai et al. ’ families Eiconaxiidae and Eiconaxiopsididae (both without uropodal suture), Coralaxiidae (lacking epipods on pereiopods 1 – 4) and from Calocarididae (in which the appendix masculina is attached terminally). Therefore, we subsume Ezaxius n. gen. to the family Axiidea. Since the first attempt to identify valuable characters to define axiid genera by Kensley & Gore (1981: Table 1), the various authors have grouped the species mainly based on the morphology of the rostrum, length ratio rostrum / eyestalk, carapace carinae, antennal acicle, maxilliped 3, symmetry of the chelipeds, pleonal pleura, telson and uropods, as well as on the presence or absence of maxilla 2 posterior lobe long setae, epipods, exopods, branchiae, pleopods 1 and 2, appendix masculina, appendix interna and / or uropodal exopod transverse suture (e. g. Poore 1994; Ngoc-Ho 2003; Sakai 2011). Some of these characters must be taken with caution because they have been demonstrated to be ambivalent. Thus, although lateral and median carapace carinae is usually constant, the submedian carina can be poorly defined or blurred in different specimens of the same species, such as in Calaxius pitatucensis (de Man, 1925) (see Sakai 2011: 104; as Colemanaxius pitatucensis), in Allaxius aethiopicus (Nobili, 1904) and in Axiopsis serratifrons (A. Milne-Edwards, 1873) (see Sakai 2011: 41, 56, respectively); moreover, postcervical carina can be posteriorly distinct in larger specimens but indistinct in smaller mature specimens, such as in Eutrichocheles modestus (Herbst, 1796) (see Sakai 2011: 112). The presence or absence of pleopod 1 can also be confusing, mainly in species descriptions based on only one specimen, because of the absence of this appendage in young specimens of some species, such as Paraxiopsis brocki (de Man, 1888), in which pleopod 1 is a segmented flagellum in large ovigerous females but lacking in small females (Sakai 1992 b: 216). Variations in the armature of several body structures, including rostrum, gastric submedian carinae, telson, third maxilliped, chelipeds, second pereiopods, uropods and the length of the scaphocerite, were also observed between holotype and paratype specimens of Formosaxius dorsum Komai, Lin & Chan, 2010 by Komai et al. (2010: 3). Our material does not share all the foregoing characters with the 19 axiid genera cited by Poore (1994), with the updated 21 axiid genera listed by Komai & Tachikawa (2007), with the 44 genera included in the Axiidae by Sakai (2011), or with the features of the axiid genus Formosaxius Komai, Lin & Chan, 2010. A triangular rostrum with lateral teeth continuous with lateral carinae, the presence of five gastric anterior carinae, the elongate antennal acicle, pleopods 3 – 5 endopods with appendix interna and the presence of a transverse suture on uropodal exopod link Ezaxius n. gen. with Albatrossaxius Sakai, 2011, Axiorygma Kensley & Simmons, 1988, Balssaxius Sakai, 2011, Guyanacaris Sakai, 2011 and Leonardaxius Sakai, 2011. However, all of them present a conspicuous posteromedian tooth on telson (vs no tooth in Ezaxius n. gen.) and none of them was described as being hermaphrodite. Moreover, Ezaxius n. gen. can be separated from Albatrossaxius, Guyanacaris and Leonardaxius by the presence of appendix masculina (vs absent in our specimen); from Balssaxius by the cervical groove distinct along the entire length (vs dorsally but not fully laterally distinct) and from Axiorygma by the absence of postcervical carina and pleopod 1 (vs presence). Therefore, while generic definitions in this family continue to be unclear or vague (Kensley & Simmons 1988; Poore 1994; see above), we describe Ezaxius n. gen. here in order to accommodate the new species Ezaxius ferachevali n. sp.	en	De Matos-Pita, Susana S., Ramil, Fran (2015): Additions to thalassinidean fauna (Crustacea: Decapoda) off Mauritania (NW Africa) with the description of a new genus and a new species. Zootaxa 4020 (3): 571-587, DOI: 10.11646/zootaxa.4020.3.9
002487F2201CFFD2FF142C82FD66FE36.taxon	materials_examined	Type material. Holotype, MNCN 20.04 / 10091 hermaphrodite, TL / CL: 23.60 / 8.80 mm (right pereiopod 1 and left pereiopod 5 are missing, both pereiopod 4 detached), Expedition Maurit 0 911, Stn MUDR 08, 19 ° 07´20 ″ N, 16 ° 50´31 ″ W, 470 m, 13 November 2009; canyon area off Cape Timiris (Mauritania); muddy coral rubble and shell debris, rock dredge.	en	De Matos-Pita, Susana S., Ramil, Fran (2015): Additions to thalassinidean fauna (Crustacea: Decapoda) off Mauritania (NW Africa) with the description of a new genus and a new species. Zootaxa 4020 (3): 571-587, DOI: 10.11646/zootaxa.4020.3.9
002487F2201CFFD2FF142C82FD66FE36.taxon	description	Description. Carapace faintly pitted, laterally compressed, dorsally rounded; cervical groove distinct dorsally, visible laterally only over one-fourth of the distance to anterolateral margin; no discernible linea thalassinica; anterior margin with outer orbital angle rounded, evenly sloping posteriorly to a rounded anterolateral margin (Figs. 3 A, 4 B). Carapace ending midposteriorly as a median lobe separate from produced posterolateral margins; median lobe with a weak short, wide dorsal carina (Figs. 3 B, 4 A). Rostrum triangular, as long as the antennular peduncle and with an upturned terminal tooth; slightly depressed below the level of gastric area; dorsal surface concave; lateral margins shortly produced posteriorly into gastric region as sharp ridges and armed with four pairs of symmetrically arranged teeth, five cut off and three regenerating, the third pair supraocular, the fourth on the short lateral carinae on anterior gastric region (Figs. 3 A – B, 4 A – B). Bristle setae are located between the rostral teeth. Gastric region with median, submedian and lateral carinae; median smooth carina, thin in base of rostrum and wide in the middle of the gastric region, barely distinguishable near the cervical groove; submedian smooth carinae in the anterior gastric region, curving anteriorly to touch each other, forming a deep inverted U-shaped area slightly elevated from rostrum, each submedian carina bearing weakly defined and elevated indentation medially; lateral carinae short, with one tooth (posterior to the supraocular) and one posterior obscure tubercle each (Figs. 3 B, 4 A). Eyes short, truncated distally and slightly angled anteroventrally, fused with carapace; cornea unpigmented (Figs. 3 B, 4 B). Antennular peduncle unarmed, reaching to rostral tip; length of article 1 twice that of articles 2 and 3 combined; article 3 about as long as article 2 (Fig. 5 L). Antennal peduncle overreaching the antennular peduncle by the total length of the ultimate article; article 1 with ventral and lateral teeth; article 2 dorsodistally elongate forming a tooth-like tubular prolongation that reaches to the distal third of article 4, and with an acutely triangular ventral prolongation (Fig. 5 M); antennal acicle unarmed, protruded straight forward and with the same shape and length of the dorsodistal tooth of article 2; article 3 with a pronounced ventrodistal tooth; article 4 about twice as long as article 5; antennal flagellum as long as the carapace (rostrum included). Maxilla 2 exopod posterior lobe (scaphognathite) with one long seta extending into branchial chamber. Maxilliped 3 pediform (ischium-merus length more than three times the merus width); coxa with a ventrodistal spine; ischium about twice as long as broad, inner crest with 11 – 12 similar denticles; merus about as long as ischium, armed with two sharp teeth subdistally on ventral margin, the distal-most more developed; carpus broadened distally, about half length of merus and about as long as propodus; dactylus about two-thirds the length of propodus; ischium, merus, carpus, propodus and dactylus ventral margin bearing pectinate setae obscured by simple setae; multiarticulate exopod hardly reaching proximal third of endopod carpus (Fig. 5 F). Left pereiopod 1 coxa armed with a distoventral spine. Basis unarmed. Ischium with 3 irregularly spaced denticles on ventral margin. Merus about twice as long as the maximum broad, armed with a subterminal tooth on dorsal margin and with 4 sharp teeth increasing in size distally on ventral margin, a few setae on distoventral and dorsal margins. Carpus dorsal length about half length of merus, unarmed, scattered groups of setae on dorsal margin and lateral surface. Chela about 2.5 times as long as broad, with tufts of setae mostly arranged longitudinally on the lateral surface, more abundant on dactylus; dorsal and ventral margins also furnished with tufts of setae (Fig. 5 G). Palm slightly longer than wide; lateral surface with a subventral crest strongly demarcate proximally, with teeth joined at base and saw-like, becoming less evident in the fixed finger; three irregular subterminal teeth below articulation with dactylus; mesial surface with two subventral tubercles distally, and five subdorsal, regularly spaced and decreasing in size (the distal subterminal, the second cut off). Propodus cutting edge with eight teeth in the proximal three-fourths decreasing in size distally, lateral surface with dentate carina on ventral margin, mesial surface with three median proximal teeth. Dactylus longer than palm, lateral surface with a median carina proximally, cutting edge armed with a proximal blunt tooth followed by a concave gap and five other blunt teeth decreasing in size distally. Distal fourth of both propodus cutting edge and dactylus are unarmed and crossing when chela is closed. Right pereiopod 1 is missing. Pereiopod 2 chelate, unarmed except by two dorsal spines on coxa, the distal one more acute, inner margins of the chelae furnished with spiniform setae; carpus about half length of merus, and about two-thirds as long as the chela; fingers slightly longer than the palm; dense row of long setae on propodus and carpus lower margins, some scarce setae distally on merus lower margins, tufts of setae on dactylus, propodus and carpus dorsal margins (Fig. 5 H). Pereiopod 3 simple, unarmed except for two dorsomesial spines on coxa; coxae with genital pore; carpus about half length of merus and slightly longer than propodus; propodus elongate, about four times longer than wide, furnished with seven stout spiniform setae on ventrolateral margin, and sparse tufts of long setae on dorsal and ventral margins; dactylus tip corneus, with two short and stout spiniform setae on lateral surface and tufts of setae on dorsal and ventral margins. Pereiopod 4 simple, unarmed except for one dorsomesial short blunt spine on a short and cylindrical coxa; carpus about half length of merus and two-thirds as long as propodus (Fig. 5 I); propodus elongate, ventrolateral margin with a longitudinal row of 7 – 8 stout spiniform setae, some of which accompanied by a supplementary spiniform seta as an interrupted second longitudinal row (Fig. 5 J), ventrodistally furnished with pectinate setae (Fig. 5 K), some sparse tufts of simple setae along dorsal margins and some single setae along ventral margin; dactylus corneus tipped and with four short, stout spiniform setae on lateral surface decreasing proximally in size (Fig. 5 J), some tufts of simple setae on dorsal and ventral margins. Right pereiopod 5 unarmed, with scattered tufts of setae on dorsal margins and lateral surfaces; coxa ventrodistally produced, with genital opening; carpus slightly longer than half of merus and as long as half of propodus; propodus mesial surface with an oblique row of pectinate setae in the distal two-fifths, ventrodistal margin produced; dactylus corneus tipped and one-fifth of propodus length. Left pereiopod 5 is missing. Exopod on maxillipeds 1 – 3; single epipod on maxillipeds 1 – 3 and pereiopods 1 – 4. Single podobranchia on maxilliped 2, and double on maxilliped 3 and pereiopods 1 – 3; single arthrobranchia on maxilliped 3 and double on pereiopods 1 – 4; pleurobranchia absent. Pleomeres smooth, unarmed and with sparse setae either single or coupled; mid-dorsal length of somites 2 – 6 subequal, slightly decreasing distally; weakly developed carina between terga and pleura on somites 2 – 5; somite 1 slightly longer than half of dorsal length of the second somite and with pleura acutely angled posteroventrally; pleura on somite 2 the widest, ventrally truncated, broadly rounded on lateroanterior and lateroposterior margins; pleura lateroanterior margin on somites 3 – 5 broadly rounded, declining backward to a rounded angle at lateroposterior margin; pleura on somite 6 rounded (Fig. 5 A). Pleopod 1 uniramous, unsegmented and distally spatulate (Fig. 5 D); pleopods 2 – 5 alike, slender, biramous, endopods with appendix interna in their proximal third (Fig. 5 C); pleopod 2 without appendix masculina (Fig. 5 E). Uropod exopod outer margin with submarginal ventral spinules barely visible dorsally in the distal third, movable tooth at posterodistal angle, just at the beginning of a clearly defined transverse suture dorsally furnished with 9 – 10 spinules; unarmed dorsal longitudinal midrib. Uropod endopod ovate, outer lateral margin with subventral spinules visible dorsally in the distal third and one distal apparent tooth; dorsal midrib with distal subterminal spine (Fig. 5 B). Telson about twice as long as wide, slightly convergent toward a rounded posterior margin without median spine; lateral margin bearing proximal lobe with spine, followed distally by two teeth each accompanied by a movable spine; half anterior dorsal surface with two short divergent carinae ending in a spine; scattered tufts of setae on dorsal surface (Fig. 5 A). Reproductive strategy. Hermaphrodite, our specimen shows clear male and female genital openings but no appendix masculina. No further details are available.	en	De Matos-Pita, Susana S., Ramil, Fran (2015): Additions to thalassinidean fauna (Crustacea: Decapoda) off Mauritania (NW Africa) with the description of a new genus and a new species. Zootaxa 4020 (3): 571-587, DOI: 10.11646/zootaxa.4020.3.9
002487F2201CFFD2FF142C82FD66FE36.taxon	discussion	Remarks. The present species closely resembles Eiconaxius borradailei Bouvier, 1905, especially because of the unarmed submedian horseshoe-shaped carinae on the anterior gastric region, the strongly protruded prolongation of the second antennal peduncle and the morphology of the pleomere pleurae (see Bouvier 1925: Pl. 7: figs. 8, 7 and Pl. 9: fig. 4, respectively). The genus Eiconaxius was described as having a weak median carina only on the rostrum, with submedian carinae converging anteriorly to join the median carina (Poore & Collins 2009). However, E. borradailei was described by Bouvier (1925: 465, Pl. 7, fig 8, Pl. 9, fig. 4) with a rostral median carina extending away from the union of submedian carinae and thickening until barely discernible before reaching the cervical groove, which concurs completely with our specimen. Moreover, other characters in the genus Eiconaxius, such as the presence of pleurobranchiae and posteromedian tooth on telson posterior margin (vs both absent in E. ferachevali) and the absence of uropodal exopod transverse suture and postcervical carina (vs both present in E. ferachevali), keep our species separate from the genus Eiconaxius and, accordingly, from E. borradailei. Habitat. The specimen was found on muddy coral rubble and shell debris at 470 m depth.	en	De Matos-Pita, Susana S., Ramil, Fran (2015): Additions to thalassinidean fauna (Crustacea: Decapoda) off Mauritania (NW Africa) with the description of a new genus and a new species. Zootaxa 4020 (3): 571-587, DOI: 10.11646/zootaxa.4020.3.9
002487F2201CFFD2FF142C82FD66FE36.taxon	materials_examined	Type locality. Off Cape Timiris area, Mauritania (19 ° 07´20 ″ N, 16 ° 50´31 ″ W), 470 m depth.	en	De Matos-Pita, Susana S., Ramil, Fran (2015): Additions to thalassinidean fauna (Crustacea: Decapoda) off Mauritania (NW Africa) with the description of a new genus and a new species. Zootaxa 4020 (3): 571-587, DOI: 10.11646/zootaxa.4020.3.9
002487F2201CFFD2FF142C82FD66FE36.taxon	etymology	Etymology. The species name derived from fer à cheval, the French expression for horseshoe, with reference to the horseshoe-shaped anterior gastric region.	en	De Matos-Pita, Susana S., Ramil, Fran (2015): Additions to thalassinidean fauna (Crustacea: Decapoda) off Mauritania (NW Africa) with the description of a new genus and a new species. Zootaxa 4020 (3): 571-587, DOI: 10.11646/zootaxa.4020.3.9
