MONDINI Nora Mariana
congresos y reuniones científicas
An integral approach to the study of late Quaternary bromalites in South America
Congreso; 6th ICAZ Taphonomy Working Group Meeting (ICAZ-TWG) - 9th TAPHOS International Meeting on Taphonomy and Fossilization; 2022
The aim of this presentation is to discuss the relevance of integrating multiple lines of evidence and different scales for the taphonomic study of bromalites, specifically palaeofeces of herbivorous and carnivorous mammals and bird pellets. Bromalites represent a specific taphonomic mode that involves the occurrence of macro and microplant remains, as well as that of vertebrates and invertebrates. The methodological approach presented here aims at integrating bromalites themselves and all of these occurrences for characterizing them, both in actualistic studies addressed at constructing frames of reference and in the analyses of fossil assemblages. The relative abundance of certain anatomical parts of vertebrate prey and their breakage and digestion patterns is key to identifying the zoological origin of bromalites of carnivorous and omnivorous animals with some taxonomic accuracy. More general patterns such as the size of all bone specimens and their surface modifications regardless of their identifiability are also informative. Other faunal contents –such as arthropods, hair, feathers and parasites– also contribute to the determination of the taxa that deposited the bromalites, and can be incorporated into the sediment even when the matrix disintegrates. The same occurs with microfossils, both of animal origin –such as spherulites, originating from the digesting organism itself– and derived from the ingested plant remains –such as pollen and silicophytoliths–. Macro plant remains may also survive the passage through the digestive tract and are informative about diet and, indirectly, about the zoological origin of bromalites. Molecular studies such as those of ancient DNA also allow identifying both the bromalites and their contents. It is important to note that some protocols favour some lines of evidence to the detriment of others. Generally, the analyses of these remains not only allows the identification of the zoological origin of bromalites but also eliciting palaeoecological information about their producers. Finally, a site and a regional approach –both in actualistic and archaeological/palaeontological studies– contributes to a better understanding of bromalite distribution in time and space and of their taphonomic implications. This integral approach to the study of bromalites will be illustrated with examples of modern and late Quaternary archaeological contexts in South America, specifically NW Argentina. These examples include actualistic studies of mammalian carnivore scats and studies of fossil carnivore and herbivore palaeofeces and raptor pellets.