Saltite uchuy, Salas & Vaccari, 2012

Salas, María José & Vaccari, N. Emilio, 2012, New insights into the early diversification of the Ostracoda: Tremadocian ostracods from the Cordillera Oriental, Argentina, Acta Palaeontologica Polonica 57 (1), pp. 175-190 : 180-181

Saltite uchuy sp. nov.

Fig. 5 .

Etymology: From Quechua language uchuy , small, in reference to the small size of the species.

Holotype: CEGH−UNC 24007 , left valve ( Fig. 5B ).

Type locality: Pascha−Incamayo area, northwest Argentina.

Type horizon: Coquina levels of the Parcha Formation, in the Angosto de Pascha section. Tr3, Hunnegraptus copiosus Biozone.

Diagnosis.— Saltite species with small and sub−elliptical valves, long and narrow lobes and broad and deep sulci. L3 is rather wide.

Description.—Valves amplete to slightly postplete, with an elliptical outline. Maximum length situated in mid−height of valves. Average L:H = 1.52. Dorsal margin straight, and only slightly shorter than maximum length of valves. Ventral and lateral margins evenly rounded. Cardinal angles obtuse. The valves have four long finger−like lobes, of which L2 does not reach the dorsal margin. L1 is adjacent to anterior margin of the valve, and is curved, with the concavity towards the posterior side. L2 is shorter than the others, straight, and vertical to slightly oblique to the dorsal margin. L3 is by far the most prominent lobe in the valve and stands just behind mid−height. Its anterior margin is straight and the posterior curved in most of the specimens. L4 is crescent−like with the concavity towards the anterior half of the valve. S1 is narrow and relatively short; S2 is broad and deep, with its margins straight and parallel. Marginal structures are lacking. The lateral surface is smooth, and in the internal moulds some specimens have sharp dots in the extra lobular surface.

Material.— About 300 specimens, shells and internal moulds, including the figured material CEGH−UNC 24006–08 , 24010–13 . Specimens we have examined range from 0.50 mm to 0.90 mm in length .

Discussion.— Saltite uchuy sp. nov. was described as undetermined binodicope by Salas et al. (2007). Here, new and abundant material, such as valves and internal moulds, is described allowing its taxonomic assignment to the genus Saltite Rossi de García and Proserpio, 1976 . Characters like the quadri lobate valves, with L3 biggest than the others lobes are the main features of the genus.

Saltite uchuy sp. nov. differs from S. erichseni ( Harrington, 1938) , which is present in San Bernardo Formation, in its relatively small size (in S. uchuy sp. nov. the maximum length is ca. 0.90 mm and in S. erichseni L is ca. 1.20 mm), and in the outline of the valves, elliptic in the new species and circular in S. erichseni . Although, the main difference between the two species are the lobes and sulci, in S. uchuy sp. nov. the lobes are finger−like and sulci are wide, mainly S2, whereas in S. erichseni the lobes are all together, only separated by slit−like sulci. In S. erichseni L3 is broader. S. uchuy sp. nov. resembles S. kuraq sp. nov., from the Humacha Member (Santa Rosita Formation) in the Humacha section, in their relatively narrow lobes and broad sulcus, however, S. uchuy sp. nov. is smaller, its fourth lobe is very well defined similar to L1, and L2 is longer whereas in S. kuraq sp. nov. is short and is joined to L1. S. uchuy sp. nov. differs from the Australian species, S. ingelorae ( Schallreuter, 1993) , by its relatively shorter lobes, and by its more defined L4. Moreover, in the Australian species L1 and L2 are very close, whereas the other sulci are broader. S. uchuy sp. nov. differs from S.? waisfeldae Salas, Vannier and Williams, 2007 mainly in its lobes, L1 and L3 have a too sharp relief, L2 is node−like, and L4 is very faint.

Stratigraphic and geographic distribution.— Saltite uchuy sp. nov. is known from the Parcha Formation and from the matrix of the Devendeus Formation in Pascha−Incamayo area, northwest Argentina. Acodus deltatus –Pariostodus proteus biozones, Late Tremadocian.

Figures

Fig. 5. Late Tremadocian soanellid ostracod Saltite uchuy sp. nov. from the Parcha Formation in the Pascha−Incamayo area of Cordillera Oriental, Argentina. A. CEGH−UNC 24006, left valve in lateral view. B. Holotype CEGH−UNC 24007, left valve in lateral view. C. CEGH−UNC 24012, internal mould of right valve in lateral view. D. CEGH−UNC 24008, internal mould of left valve in lateral view. E. CEGH−UNC 24010, internal mould in dorsal view. F. CEGH−UNC 24011, internal mould in ventral view. G. CEGH−UNC 24013, internal mould of right valve, lateral view. Scale bars 100 µm.