First hexactinellid spicules from the Late Cambrian olitofish of the Los Sombreros Formation, Tontal Range, San Juan Precordillera, Argentina

Abstract

A moderately diverse fauna of hexactinellid sponges is described from one Late Cambrian olitofish of the Los Sombreros Formation from Tres Saltos Gulch in the Tontal Range, Western Precordillera, San Juan Province. Argentina. Protospongia sp., Diagoniella ? Sp., Kiwetinokia , anchoring spicules, prodiaenes, diagonally arranged spicules and root tuft are present. The preservation degree of the spicules and the patterns allow us to presume that after their death, they were transported not very far from the original sponges oases. The Cambrian oolitic grainstone limestone with spicules conform an olitofish which was transported and resedimented during the Ordovician by gravity flows within a pelitic matrix of the terrigenous-carbonate talus of the Los Sombreros Formation.