INSTITUTO SUPERIOR DE CORRELACION GEOLOGICA
Unidad Ejecutora - UE
Chronostratigraphy and significance of the Rugosa Group (Cruziana, trace fossil) in the Ordovician strata of the South American Central Andean Basin
ACEÑOLAZA G.; HEREDIA S.; CARLOROSI, J.
COMPTES RENDUS PALEVOL
ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER
Lugar: Paris; Año: 2015 vol. 14 p. 85 - 85
tAlthough most trace fossils display long temporal ranges, certain forms as the Paleozoicmostly trilobite trace Cruziana have particular biostratigraphic significance. The evolutionand replacement of trilobite families during the Paleozoic are reflected by the mor-phological characteristics of trace fossils that have contributed to interpret ages in the?non-fossiliferous? shallow marine Gondwanan realm. The ?Cruziana stratigraphy? con-cept is based on this scheme, where different sets of traces replace each other on thestratigraphical record. The Cruziana rugosa Group is part of this scheme, and has been clas-sically mis-referred as an exclusively Lower Ordovician element in the Central AndeanBasin of South America. This contribution reevaluates the presence of the C. rugosa Groupin the Lower to Middle Ordovician strata of the Cordillera Oriental and Subandean ranges ofArgentina and in the Lower to Upper Ordovician of the Cordillera Oriental and Subandeanranges of Bolivia, and highlights its original distribution on its type area. The current paperdisplays a biostratigraphically-supported analysis of its record, also contributing with littleknown data from the northern sector of the continent, in the Colombian Andes.