Abstract

ZEBALLO, Fernando J.; ALBANESI, Guillermo L.  and  ORTEGA, Gladys. Conodont and graptolite faunas from the Alfarcito and Rupasca formations (Tremadocian) from the Alfarcito area, Tilcara, Oriental Cordillera of Jujuy, Argentina. Part 2: Systematic palaeontology. Ameghiniana [online]. 2005, vol.42, n.1, pp.47-66. ISSN 1851-8044.

A systematic analysis of conodont and graptolite faunas from the Alfarcito and Rupasca Formations, exposed at the Alfarcito area, Cordillera Oriental of Jujuy, is presented. Described species correspond to the Cordylodus angulatus and Paltodus deltifer zones ( Paltodus deltifer pristinus Subzone) from the late early to early late Tremadocian (Lower Ordovician). Studied conodonts represent 7 families, 14 genera, and 23 species. Five new species are diagnosed among described and illustrated forms, i.e. , Drepanoistodus alfarcitensis n. sp., Drepanoistodus n. sp. A, Semiacontiodus striatus n. sp., Semiacontiodus minutus n. sp. and Utahconus n. sp. A. Likewise, the record of Rhabdinopora flabelliformis flabelliformis (Eichwald) from top strata of the Alfarcito Formation, is reported and discussed.

Keywords : Conodonta; Graptolithina; Early Ordovician; Alfarcito; Jujuy; Argentina.