Cyprideis ituiae, Gross & Ramos & Piller, 2014

Gross, Martin, Ramos, Maria Ines F. & Piller, Werner E., 2014, On the Miocene Cyprideis species flock (Ostracoda; Crustacea) of Western Amazonia (Solimões Formation): Refining taxonomy on species level, Zootaxa 3899 (1), pp. 1-69 : 29-30

publication ID	https://doi.org/ 10.11646/zootaxa.3899.1.1
publication LSID	lsid:zoobank.org:pub:D78F2010-08E1-45C0-86FF-7F2D3601070D
persistent identifier	https://treatment.plazi.org/id/017587FE-FFB0-FFDA-71F4-DAB0FAA1FA88
treatment provided by	Felipe
scientific name	Cyprideis ituiae
status	sp. nov.

Treatment

Cyprideis ituiae View in CoL n. sp.

Figs. 6j–k View FIGURE 6 ; Pl. 11, Figs. 1 View FIGURE 1 –50

Holotype. Right female valve, AM10-23 _18 (Inv. No. MPEG-309-M; coll. Museu Paraense Emílio Goeldi, Belém; Pl. 11, Figs. 19–20, 47–49).

Paratypes. Additionally figured specimens ( Figs. 6j–k View FIGURE 6 ; Pl. 11, Figs. 1 View FIGURE 1 –18, 21–46, 50; coll. Museu Paraense Emílio Goeldi, Belém).

Additional material. 315 adult and 13 juvenile specimens from samples AM10 /15, 19, 22–23, 25, 27, 29–30 (Inv. No. UMJG & P 211.038 ; coll. Universalmuseum Joanneum, Department for Geology & Palaeontology, Graz) .

Type locality. Borehole 1AS-10- AM at Sucuriju close to Rio Ituí (S 04°50’ / W 70°22’, ~ 62 km SW Benjamin Constant; municipality Atalaia do Norte, state of Amazonia, Brazil) GoogleMaps .

Type horizon. Sample AM10 /23 (= depth: 118 m, altitude: - 33 m) .

Derivation of name. Rio Ituí (river in western Amazonia), where well 1AS-10- AM has been drilled.

Diagnosis. A reticulated to coarsely punctated Cyprideis -species with strong, distally broadened and indented anteromarginal denticles and distinct, groove-like sulcus.

Description. Subrectangular (female) or subtrapezoidal (male) outline in lateral view. Surface reticulated to coarsely punctated; dorsomedian sulcus prominent and anteroventrally orientated; flange anteromarginally and posteroventrally thick, forming a robust rim; reticulum anteroperipherally reduced to a row of low, sub-squarish meshes behind which the surface is smooth or micro-punctate. About 7, distally expanding, indented anteromarginal denticles of which the uppermost and smallest one is cone-shaped and located just above the half of valves’ height; up to 6, well-developed posteroventral spines in right valves with the spine in the posteroventral corner being the longest one; below, already on the ventral margin, one additional, strong posteroventral spine is sometimes developed. Numerous, roundish normal pores of sieve type. Inner lamella moderately wide with numerous straight, occasionally branched marginal pore canals; avestibulate. Hinge (right valve): anterior element elongate with ~9 toothlets; short anteromedian element with 3 larger sockets; long posteromedian element consisting of a crenulated bar; posterior element with ~7 toothlets; hinge elements of left valve complementary. Central muscle scars consist of 4 adductor scars, 1 U- or V-shaped frontal and 2 mandibular scars (the upper one round–elongate; the lower, oval one located close to the ventral margin); prominent fulcral point (knob). Sexual dimorphism distinct: males are more elongated with the posterior margin more oblique. Juveniles are subtriangular in lateral view; the hinge and especially the inner lamella are weakly developed.

Dimensions (total range over all samples). R ♀ l = 0.59–0.78 (0.66), h = 0.29–0.36 (0.33; n = 50); L ♀ l = 0.62–0.76 (0.68), h = 0.31–0.40 (0.35; n = 34); R ♂ l = 0.69–0.81 (0.74), h = 0.31–0.37 (0.34; n = 17); L ♂ l = 0.69–0.82 (0.76), h = 0.34–0.39 (0.36; n = 22); Rj(A-1) l = 0.52–0.61 (0.57), h = 0.27–0.31 (0.29; n = 2); Lj(A-1) l = 0.60–0.61 (0.61), h = 0.31–0.32 (0.32; n = 2). See also figure 5.

Remarks. This species is very characteristic due to its distally widened, teeth-like anterior spines. C. ituiae is similar to C. pebasae from which it differs by the shape of the anterior spines (in C. pebasae they are pointed) and the well-developed sulcus, which forms a dorsomedian groove ( C. pebasae is asulcate). While in C. pebasae posteroventral spines (right valves) are inconspicuous, C. ituiae bears longer spines with the most developed spine placed in the posteroventral-corner (occasionally an additional, long spine is observable on the ventral margin (e.g. Pl. 11, Figs. 23–24, 49). Further, the ornament of C. ituiae is reduced anteroperipherally (tiny puncta to almost smooth), behind a thick flange (e.g. Pl. 11, Figs. 45, 47).

Occurrence. Western Amazonia ( Brazil, this study), latest Middle to early Late Miocene ( C. obliquosulcata – C. cyrtoma zone; this study; chronostratigraphic correlation after Wesselingh & Ramos 2010).