Comparative analysis of the Early Ordovician Baltograptid species of Northwestern Argentina, Baltoscandia and South China.

TORO, B.A; MALETZ, J.; ZHANG, YD.; ZHANG, J.

Ordovician of the World

Instituto Geológico Minero de España

Lugar: Madrid; Año: 2011; p. 597 - 603

Deflexed two-stiped graptolite species from NW Argentina were considered as indicators of Arenigian age since the 1960’. However, only in recent years different authors reevaluated the records of a number of Argentinean deflexed baltograptids and pointed out the importance of these forms for the accuracy of the biostratigraphic scheme and the regional correlation previously proposed in the Central Andean Basin. Toro and Maletz (2007) analyzed a number of well-preserved specimens of the genus Baltograptus and related forms from several Floian sections in the Argentinean Eastern Cordillera. They highlighted the relevance of this group in the regional biostratigraphic framework as well as tackled remaining questions regarding the international distribution of Baltograptus. This paper deals with the analysis of additional graptolite material from the Lumara and Santa Victoria areas of Northwest Argentina and the equivalent graptolite faunas recently reviewed from SW China and Sweden. The main objectives of this research are the confirmation of previous regional results and the integration of the new information into the international biostratigraphic and taxonomic framework.