Unraveling one of the ‘ Big Five’: update of the taxonomy of Triphoridae (Gastropoda, Triphoroidea) from Brazil Author Fernandes, Maurício Romulo 3B8B864F-3300-45B2-8D1F-61F282F83CDE Departamento de Zoologia, Instituto de Biociências, Universidade Federal do Estado do Rio de Janeiro, Av. Pasteur, 458, Urca, 22290 - 240, Rio de Janeiro, Brazil. & Departamento de Invertebrados, Museu Nacional, Universidade Federal do Rio de Janeiro, Quinta da Boa Vista, São Cristóvão, 20940 - 040, Rio de Janeiro, Brazil. mauriciofernandes14@hotmail.com Author Pimenta, Alexandre Dias 2A42AE1F-6AF8-4AB3-975C-D3CE4D678F22 Departamento de Invertebrados, Museu Nacional, Universidade Federal do Rio de Janeiro, Quinta da Boa Vista, São Cristóvão, 20940 - 040, Rio de Janeiro, Brazil. alexpim@mn.ufrj.br text European Journal of Taxonomy 2020 2020-06-12 665 665 1 170 journal article 10.5852/ejt.2020.665 06748f67-18d9-4c3e-a14c-77de1664d81b 2118-9773 3899047 836C9171-0849-4F4D-BC8D-90C2D9E8B9D1 Nanaphora sp. 1 Figs 12 , 23S , 60 Material examined BRAZIL – Rio Grande do Norte • 1 spec. ; 04º41′20″ S , 36º34′45″ W ; depth 145 m ; 22 May 2011 ; MNRJ 35177 *. Description Shell sinistral, inflated, biconical/ovoid, convex profile, 2.9 mm long, 1.2 mm wide, length/width ratio 2.5. Protoconch multispiral, conical/columnar, 0.40 mm long, 0.36 mm wide, four convex whorls; embryonic shell dome-shaped, eroded; larval shell with two spiral cords, situated at ~41% and ~66% of penultimate whorl height, the adapical cord disappears in the last whorl; ~28 nearly rectilinear axial ribs. Teleoconch with 6.5 whorls; two spiral cords (adapical and abapical) at beginning, abapical one continuous to that of protoconch; median spiral cord emerges in fourth whorl, reaching same size of other cords after 1.5 whorl; on body whorl, spiral cords are as wide as distance between them; 24 nearly orthocline axial ribs in sixth whorl; rounded nodules of medium size; distinct suture, with very small sutural cord; wavy subperipheral cord, two nearly smooth basal cords; no supranumerical cords; elliptical aperture, 0.69 mm long, 0.44 mm wide, length/width ratio 1.5; anterior canal curved backwards/ downwards, short, partially open, 0.11 mm long, 0.22 mm wide, length/width ratio 0.5; posterior canal as small sinus, 0.08 mm long. Shell beige, nodules of teleoconch slightly clearer than internodular spaces. Fig. 12. Nanaphora sp. 1. A–F . MNRJ 35177*, 2.94 mm. Scale bars: A–B = 1 mm; C–E = 500 µm; F = 100 µm. Remarks The most similar species to Nanaphora sp. 1 is Triphora turtlebayensis Rolán & Lee, 2008 , both sharing a distinct ovoid shell shape. However, T . turtlebayensis has a paucispiral protoconch and is restricted to Bermuda . Nanaphora sp. 1 is also superficially similar to the western Atlantic species Nanaphora verbernei ( Moolenbeek & Faber, 1989 ) , but mainly distinguished by an earlier emergence of the median spiral cord of the teleoconch ( Fig. 12B ) and by the smoothness of the subperipheral and basal cords ( Fig. 12D ). Nanaphora sp. 1 is herein regarded as belonging to this genus especially owing to its shell shape and to the small size of its protoconch, although this species has smaller nodules of the teleoconch when compared to typical species of Nanaphora , and its embryonic shell sculpture remains unknown due to erosion. Geographical records Brazil : Rio Grande do Norte . Bathymetric distribution Only known from 145 m depth.