Nanaphora sp. 1, Laseron, 1958

Fernandes, Maurício Romulo & Pimenta, Alexandre Dias, 2020, Unraveling one of the ‘ Big Five’: update of the taxonomy of Triphoridae (Gastropoda, Triphoroidea) from Brazil, European Journal of Taxonomy 665 (665), pp. 1-170 : 30-31

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.

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.

Figures

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.

Fig. 23. Triphoridae from Brazil (2). A. “Inella” sp. 4. B. Iniforis carmelae Rolán & Fernández- Garcés, 1993. C. Iniforis pseudothomae Rolán & Fernández-Garcés, 1993. D. Isotriphora leo sp. nov. E. Isotriphora onca Fernandes, Pimenta & Leal, 2013. F. Isotriphora tigrina Fernandes, Pimenta & Leal, 2013. G. Isotriphora tricingulata Rolán & Fernández-Garcés, 2015. H. Isotriphora uncia sp. nov. I. Isotriphora sp. 1. J. Latitriphora albida (A. Adams, 1854). K. Marshallora sp. L. Marshallora ostenta Rolán & Fernández-Garcés, 2008. M. Marshallora sp. 1. N. Monophorus caracca (Dall, 1927) comb. nov. O. Monophorus olivaceus (Dall, 1889). P. Monophorus verecundus sp. nov. Q. Nanaphora leei Fernandes & Pimenta, 2015. R. Nanaphora verbernei (Moolenbeek & Faber, 1989). S. Nanaphora sp. 1. Scale bars: 1 mm.

Fig. 60. Distribution map of Nanaphora sp. 1.