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12Juan (Beresi and Banchig 1997). A synthesis of the Cambriansponge occurrence in the Argentine Precordillera was givenby Beresi (2003a).Silicified sponge spicules from residues of conodonts fromdiverse Cambrian and Ordovician sections in the Precordillera,were described by Mehl and Lehnert (1997). Anthaspidellidskeletal fragments from the Middle Cambrian rocks of thePrecordillera, in the province of San Juan, document the onlyknown occurrence from South America (Beresi and Rigby1994). Protachileum kayseri Zittel, 1877 from the San Juanprovince, was the first report of a Precordilleran sponge.Taxonomic studies have been concentrated in the rich spongefauna of the warm carbonate platform (San Juan Formation)from the Lower-Middle Ordovician of the Precordillera basin(Beresi and Rigby 1993, Carrera 1996a, 1996b).The purpose of this paper is to review the occurrence offossil sponges and their biostratigraphic distribution in thediverse geological provinces of Argentina.Cambrian and Ordovician fauna from theNorthwest Argentinian regionSiliciclastic sediments with minor carbonates dominatethe Cambrian and Ordovician of Northern Argentina andthe Central Andean Basin of South America. Cambrian andOrdovician sponges and spicules from Northwest Argentinaprovide additional paleontological data from the siliciclasticplatforms of western Gondwana.PunaIn the Puna region (Fig. 1A-B), a single specimen (Fig.2M-N) of a complete Ordovician hexactinellid sponge wasdiscovered. It has been collected from volcaniclastic rocksof the Las Vicuñas Formation (Tremadocian) in Lari Creek,southwest of the Salar del Rincon area, Salta province,Argentina. The material was assigned to the new genus andspecies Larispongia magdalenae (Carrera, 1998), that belongto the family Pelicaspongiidae, and it is the first record of thefamily in western Gondwana.Subandean RangesThe first report on the occurrence of one completelypreserved hexactinellid sponge is a part and counterpart of around small sponge described as Diagoniella sp. (Beresi et al.2006). This sponge (Fig. 2H) was reported for the first timefrom the Upper Cambrian-Lower Ordovician siliciclasticrocks of the Orcomato Formation, in the Candelaria Range,Sub-Andean Ranges, in Salta Province (Fig. 1B).The fossiliferous record of the unit suggests a Cambrian-Ordovician age. The sponge is preserved in greenishyellowishshales, as dark stained flattened rounded bodies(somewhat deformed and fragmentary).Fig. 1: A. South America showing the position of Argentina. B.Location of the Basins of Argentina with sponge fauna: (Pu) Puna;(CO) Cordillera Oriental, (SS) Sierras Subandinas, (F) Famatina,(Pa) Paraná basin, (P) Precordillera, (SR) San Rafael Block, (N)Neuquén basin, (MP) North Patagonian Massif. C. Map of Argentineshowing the San Juan and Mendoza provinces. D. Sponge localitieswithin the Precordillera Precordillera of San Juan and northernMendoza provinces.Eastern CordilleraHexactinellid meshes of Protospongia (Beresi et al. 2006)were recently reported from Lower Tremadocian siliciclasticsediments in the Eastern Cordillera, Salta Province (Fig. 1).The hexactinellid spicules were recovered from the lower