Cyprideis schedogymnos Muñoz-Torres, Whatley & Van Harten, 1998

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 : 23-25

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-FFBA-FFDF-71F4-D803FEF5FEB8
treatment provided by	Felipe
scientific name	Cyprideis schedogymnos Muñoz-Torres, Whatley & Van Harten, 1998
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Fig. 6c View FIGURE 6 ; Pl. 6, Figs. 22, 24–32

* 1998 Cyprideis schedogymnos sp. nov. —Muñoz-Torres et al.: 100; Text-fig. 2; Pl. 4, Figs. 11–15.

Material. 62 valves; samples AM 10/41–44.

Dimensions (total range over all samples). R ♀ l = 0.76–0.82 (0.79), h = 0.39–0.40 (0.40; n = 4); L ♀ l = 0.78–0.80 (0.79), h = 0.42–0.43 (0.43; n = 3); R ♂ l = 0.87, h = 0.42 (n = 1); L ♂ l = 0.88, h = 0.44 (n = 1).

Remarks. C. schedogymnos occurs only in the lowermost productive samples in the present core. It largely resembles C. cyrtoma , from which it differs by the lack of the “downturned” anterior margin causing a prominent ventral concavity in both valves of C. cyrtoma , which is almost missing in C. schedogymnos ( Muñoz-Torres et al. 1998) . C. cyrtoma has a more extended posteroventral flange with up to five denticles and usually one long spine in the posteroventral corner of right valves (Pl. 6, Fig. 23). C. schedogymnos lacks such a main spine and the denticles are smaller (Pl. 6, Fig. 24). C. schedogymnos is a smooth species except some posteroperipheral puncta and “plications” (a row of thick walled fossae) behind the strong anteromarginal rim (Pl. 6, Fig. 22; Muñoz-Torres et al. 1998). C. cyrtoma misses these plications; instead, it has a smooth groove following the course of the anterior border (Pl. 6, Fig. 21). Furthermore, C. cyrtoma has a weak, sinuous sulcus, whereas C. schedogymnos is almost asulcate.

Typically, the surface of C. cyrtoma is smooth in front of the sulcus and punctate behind it. However, considerable variability of ornamentation is observed, ranging from almost smooth to punctate (except the area behind the anterior margin) specimens, which weakens this diagnostic character (see above).

In the phylogenetic model of Muñoz-Torres et al. (2006) C. schedogymnos and C. cyrtoma are placed in two different lineages ( C. cyrtoma : “ornate”, C. schedogymnos : “smooth lineage”). In contrast, we suggest that both are much closer related and belong to the same lineage ( Fig. 3a View FIGURE 3 ).

Occurrence. Western Amazonia ( Brazil (this study), Peru), Middle Miocene ( C. caraionae – C. minipunctata zone; Muñoz-Torres et al. 2006; chronostratigraphic correlation after Wesselingh & Ramos 2010).

4.6.2. graciosa subgroup

Species. C. graciosa , C. reticulopunctata , C. minipunctata , C. curucae , C. longispina (the latter not among the present material); possibly C. anterospinosa , C. marginuspinosa , C. retrobispinosa (all not among the present material and re-examination pending).

Characters. Subrectangular, subtriangular or subovate; medium to large sized; punctated to reticulated, sulcate; with spines/denticles along the entire or the two lower thirds of the anterior margin (both valves) and posteroventral spines in right valves (except C. retrobispinosa ; due to reversed overlap in left valves), some with posteroventral spines in both valves ( C. graciosa , C. reticulopunctata ); essentially moderately wide inner lamella, avestibulate; anterior simple or few bifurcated marginal pore canals; generotypic hinge ( C. retrobispinosa with inverse hinge).