Scutoplites azorensis, Reverter-Gil & Souto & Berning, 2025

Scutoplites azorensis sp. nov.

( Fig. 8 View FIGURE 8 ; Table 5 View TABLE 5 )

Material examined. Holotype: MHNUSC 10157 : D11, Iberia Seamount “ Top of Bolinha ”, 39º19’53.01’’N, 29º45’06.59’’W, 1230 m, 5 Jul. 2019 (sample EX2_D11_R14B10), fragment a ( Fig. 8 A, B View FIGURE 8 ) and fragment b ( Fig. 8 C–F View FIGURE 8 ) dry, fragment c in alcohol. GoogleMaps

Etymology. The name azorensis alludes to the geographic origin of the studied material.

Description. Colony erect, dichotomously branching. Branches formed by two series of alternating autozooids opening on one side only. Branching points composed of a single proximomedian autozooid and two distolateral ones.Autozooids elongate, relatively stout, with the distal half of the autozooid slightly turned outwards alternatingly to right or left. Distal half of autozooid occupied by a large, oval, membranous area, covered proximally by a convex flabelliform scutum that is elongate oval, longer than wide, and attached to the inner proximal angle of orifice; scutum margin merging with the circum-opesial gymnocyst, with about 16–21 narrow, radial fissures that are variable in length, leaving a wide, imperforated central area. The distal edge of the scutum projects as a straight lip that delimits the opercular area, which is clearly wider than long. Operculum thickly sclerotised. One small spine inconstantly present on the inner side of the orifice. Outer distal angle of autozooids with two (rarely three) stout spines that can reach twice the length of an autozooid. Median autozooid in the branching point with one single spine located on the opposite side of the base of the scutum.

Adventitious avicularia of two kinds: one small, located mediolaterally to the scutum and displaced towards the basal side, difficult to see in frontal view, with the triangular mandible obliquely directed proximally and outwards; another small avicularium on a raised cystid just proximally to scutum, its triangular mandible directed proximally and upwards/terminally. Mandibles in both avicularia hinged on inconspicuous condyles.

Ovicell large, globular, prominent, resting on the proximal part of the distal autozooid, sack-shaped and much longer than wide, reaching the proximal margin of the scutum; surface somewhat uneven and with a proximomedian drop-shaped fenestra pointing proximally, the proximolateral ooecial margins reaching towards mid-distance of lateral orifice rim, ovicell opening well arched above orifice.

An ancestrula was not observed.

Remarks. Only one colony was collected, now divided into three fragments, two dry and one in alcohol, all of them designated here as the holotype of the species. The external spines, although frequently broken, can become very long and show obvious signs of regeneration after breaking ( Fig. 8 View FIGURE 8 , A, B).

Scutoplites marsupiatus n. comb. differs from the new species in that the scutum is nearly as wide as long and has relatively longer fissures, in a single spine that is present in each distal angle, and in a large lateral avicularium, whereas in S. azorensis sp. nov. the scutum is clearly longer than wide, the fissures are shorter, leaving a wide central imperforated area, there are two (or even three) stout outer spines, and the lateral avicularium is difficult to see in frontal view. Moreover, the operculum in S. marsupiatus n. comb. is as wide as long and the ovicell is very long, but in S. azorensis sp. nov. the operculum is clearly wider than long, and the ovicell, although it is also long, is shaped like a sack.

Scutoplites saojorgensis n. comb. has a scutum that is wider than long, with the fissures normally alternating between a long and a short one, lacks spines, bears a visible lateral avicularium, the orifice is displaced towards the outer autozooid margin, and the ovicell bears a triangular fenestra.

Scutoplites clausus n. comb. has fewer and shorter fissures, which are also absent in the inner margin of the scutum, and the ovicell is clearly shorter. In S. reverteri n. comb. there are six stout, pointed spikes and the scutum has much larger fissures. In S. hamartia sp. nov. the scutum is also large and elongate oval but it has a broad and strongly recurved base and longer digital branch prolongations. Moreover, the outer distal angle of the autozooid bears a single spine instead of two. Finally, in S. virgulus sp. nov. the scutum is almost circular, only slightly longer than wide, with fewer fissures while there are none in the inner edge of the scutum; the lateral avicularium, though small, is visible in frontal view; there is one single inconstant spine in the outer angle; and finally, the ovicell is shorter.

At present, S. azorensis sp. nov. is known only from 1230 m depth on Iberia Seamount, which is situated on the Mid-Atlantic Ridge halfway between the central and the western groups of Azorean islands.