This article explores the levels of fragmentation and fracture patterns in archaeofaunal assemblages from the lower basin of the Colorado River (Argentina) following Outram's methodology. Remains of ungulates (guanaco) have suffered, in these assemblages, a high degree of fragmentation probably caused during the processing of the carcasses. The presence of helical debris and shaft fragments indicates that fragmentation would respond to processing tasks for the consumption of marrow and possibly bone grease. The results of the application of this methodology that were obtained from the analysis of three late Holocene sites (La Primavera, Loma Ruiz 1 and El Tigre) are presented. These results provide new evidence not only for patterns of marrow and bone grease consumption but also for dealing with the subsistence model proposed for the study area. In this sense, the intensification processes already proposed during the final late Holocene (1000–250 bp) are discussed. Copyright © 2012 John Wiley & Sons, Ltd.