Saltite kuraq, 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 : 181-182

Saltite kuraq sp. nov.

Fig. 4D–H .

Etymology: from Quechua language kuraq , the biggest, in reference to the big size of the species.

Holotype: CEGH−UNC 23999 , internal mould of left valve ( Fig. 4G ).

Type locality: Quebrada de Humahuaca area, in Quebrada de Humacha section, northwest Argentina.

Type horizon: PN sample, A. victoriae Biozone , partly equivalent with A. deltatus – P. proteus biozones, Tr3, Humacha Member of the Santa Rosita Formation.

Diagnosis.— Saltite species with L2 short and tilted to the anterior half of the valves, L2 meets with L1.

Description.—Valves amplete and sub−elliptical in lateral outline. L:H ratio is 1.57. The maximum length is situated near the dorsal margin. The dorsal margin is straight and slightly shorter than L. The lateral margins are rounded to lightly straight and the ventral margin is rounded. Well defined and obtuse cardinal angles, with the anterior slightly bigger than the posterior one. The valves are quadri lobated. The lobes are well defined and perpendicular to dorsal margin or slightly tilted away from it. L1 and L2 are in the anterior half of the valves, they are generally thin and rounded. L1 reaches or overreaches dorsal margin, L2 is shorter and is tilt to the anterior half of valves and meets with L1. In some specimens the lobes are shorter, only well defined in the dorsal half of the valves. Axis of L3 corresponds approximately to midline of valve or is slightly behind it. L3 is the most prominent lobe, it overreaches the dorsal margin, and it is broad in the base and tapering to the dorsal end. L4 varies from well defined to a faint elevation near the posterior end of the valves. The lateral surface is punctuated, however, this feature is visible in only two specimens, the preservation of the material is not so good.

Material.— Around 100 specimens of internal and external moulds, and latex cast, including the figured material CEGH−UNC 23999–24000 , 24002 , 24004–05 . Specimens we have examined range from 0.53 mm to 1.4 mm in length .

Discussion.—The main difference between Saltite kuraq sp. nov. and the other species of the genus is the joint between L1 and L2, a feature that is not observed in any of the other forms. Moreover, S. kuraq sp. nov. differs from S. uchuy sp. nov., from the Parcha Formation, in the posterior lobe. In the described species L4 varies from poorly defined to very well defined; there are specimens in which L4 is a faint lobe. In S. uchuy sp. nov. L4 is always well developed and similar to L1. On the other side, S. kuraq sp. nov. is bigger than the Pascha specimens. S. kuraq sp. nov. varies from S. erichseni mainly in its narrower lobes and broader sulcus. In the new species the valves are sub−elliptic whereas in S. erichseni the valves are subcircular. The length of the valves is similar in the two species, however, S. kuraq sp. nov. is larger in size. S. ingelorae ( Schallreuter, 1993) , the Australian species, has very long and thin lobes, with wide sulci between each other, and is smaller than the Argentinian species.

Stratigraphic and geographic distribution.—Known from the upper part of the Humacha Member in the Quebrada de

http://dx.doi.org/10.4202/app.2009.1110

Humacha section, and in the Coquena Formation in the Quebrada de Chalala section, northwest Argentina. Tr3 ( Araneograptus victoriae , Acodus deltatus –Pariostodus proteus biozones).

Figures

Fig. 4. Late Tremadocian soanellid ostracods from the Cordillera Oriental Argentina. A–C. Saltite erichseni (Harrington, 1938). San Bernardo Formation from Cerro San Bernardo section. A. CEGH−UNC 21150, internal mould of left valve, lateral view. B. CEGH−UNC 21149, internal mould of right valve, lateral view. C. CEGH−UNC 23994, external mould of right valve, lateral view. D–H. Saltite kuraq sp. nov. Humacha Member of Santa Rosita Formation from Humacha section. D. CEGH−UNC 24004, internal mould of left valve, lateral view. E. Holotype CEGH−UNC 23999, internal mould of left valve, lateral view. F. CEGH−UNC 24000, internal mould of left valve, lateral view. G. CEGH−UNC 24002, external mould of left valve, lateral view. H. CEGH−UNC 24005, external mould of right valve, lateral view. Scale bars 100 µm.