The Lower Pliocene marine gastropods of Santa Maria Island, Azores: Taxonomy and palaeobiogeographic implications Author Sacchetti, Claudia 0000-0002-3225-3139 claudiasacc@icloud.com Author Landau, Bernard 0000-0002-7768-8494 bernardmlandau@gmail.com Author Ávila, Sérgio P. 0000-0002-3225-3139 claudiasacc@icloud.com text Zootaxa 2023 2023-05-24 5295 1 1 150 http://dx.doi.org/10.11646/zootaxa.5295.1.1 journal article 53396 10.11646/zootaxa.5295.1.1 82286fdc-a858-447c-9980-da2e8985d19c 1175-5326 7965273 F3A52660-70B8-439F-A7A0-F45ADC975EA5 Euspira atlantica (Mayer, 1862) Plate 2 H 1 -H 2 * Natica Atlantica Mayer , in Bronn in Reiss 1862: 33 . Natica atlantica Mayer — Mayer 1864: 64 , pl. 6, fig. 45. Type material. Four specimens, dimension not stated, Pinheiros, Santa Maria Island, Azores ; One specimen, dimension not stated, Boca do Cré (= Cré), Santa Maria Island, Azores ; whereabouts unknown ( Beu 2017:165 ). Santa Maria material examined. Maximum height 16.0 mm, diameter 19.0 mm. Two specimens from LNEG collection (unnumbered specimen), Ponta do Norte lighthouse, Santa Maria Island, Azores , Touril Complex, Lower Pliocene. Original description. “ Einige unvollkommene Exemplare einer nicht grossen Ei-f̂rmig kugeligen glatten Art aus der Gruppe der N. helicina mit einfacher Zuwachsstreifung, wie so viele andere, deren Eigentḩmlichkeit aber in der Modifikation des Nabels liegt, die sich indessen leichter bildlich darstellen als hinreichend genau in Worten ausdŗcken lässt. Der Spindel-Rand verlängert sich nämlich ziemlich weit vorwärts, ehe er in den Vorderrand fortsetzt, und lässt hinten zwischen sich und dem vorigen Umgang an der Stelle des Nabels eine lange schmale und ziemlich tiefe, aber nicht in die Spindel eindringende Rinne, welche sich gegen die M̧ndung einwärts biegt und in diese ausm̧ndet, bevor der innere in den vorderen Rand ̧bergeht [Some imperfect specimens of a not large eggshaped spherical smooth species from the group of N. helicina with simple growth lines, like so many others, but whose peculiarity lies in the modification of the umbilicus, which, however, is easier to visualize than to express sufficiently accurately in words. The spindle edge extends quite far forward before continuing into the front edge, leaving a long narrow and rather deep channel at the back between itself and the previous whorl at the umbilicus, which bends towards the mouth inwards and ends into it before the inner edge merges into the front edge.]” (Bronn in Reiss 1862: 33 ). Latin description. “ Testa subglobosa , obliqua, laevigata , tenuiuscula; anfractibus quinque subdepressis, subcontiguis; spira prominula, acutiuscula; apertura semilunari; umbilico parvo, callo angusto, elongato, semitecto .” ( Mayer, 1864: 64 ). Discussion. Mayer (1864: 64) compared the Azorean species to Natica helicina Brocchi, 1814 , and N. guillemini [ sic ], both of which are now included in the genus Euspira . The original description and figure are insufficient to adequately characterise this species. The Azorean material at hand is all decorticated and missing their apex. This might explain the peculiar umbilical characters described by Mayer (see above). No further determination can be made, and we provisionally accept Mayer’s species. Distribution. Lower Pliocene: Atlantic, Santa Maria Island, Azores (Bronn in Reiss 1862 ; Mayer 1864 ).