Abstract

WAISFELD, Beatriz G.  and  VACCARI, N. Emilio. Revision of the Ogygiocaris Araiorhachis Zone (Trilobita, Late Tremadocian) in the Paschaincamayo Region, Cordillera Oriental, Argentina: Part 2: Systematic. Ameghiniana [online]. 2006, vol.43, n.4, pp.729-744. ISSN 1851-8044.

A revision of the late Tremadoc Ogygiocaris araiorhachis trilobite Zone recorded in the Saladillo and Parcha Formations (Pascha-Incamayo area, quebrada del Toro, Salta Province) is given here. This second part involves the systematic study of the trilobite fauna. New material of O. araiorhachis Harrington and Leanza has provided a better understanding of the morphology of the species and new insights for its classification. Araiocaris Pribyl and Vanek and Ogygiocarella Harrington and Leanza are considered to be synonymous with Ogygiocaris Angelin. Hence, the latter genus involves species from the Baltic region, Great Britain and Argentina O. araiorhachis being the earliest species of the genus to exhibit a wavy paradoublural line and a wavy inner margin of the doublure. Two new species: Bienvillia jana sp. nov., B. kichka sp. nov. are described. In addition, B. parchaensis Harrington and Leanza, Hypermecaspis armata Harrington and Leanza, H. inermis Harrington and Leanza, Hypermecaspis sp. nov., Hypermecaspis sp., Psilocara liliae Tortello, Megistaspis (Ekeraspis)? sp., Kayseraspis sp. and Thysanopyge taurinus (Harrington) are also recognized.

Keywords : Trilobites; Systematics; Late Tremadocian; Pascha; Cordillera Oriental; Argentina.