Multiproxy diet analysis of the last meal of an early Holocene Yakutian bison

Pollen, botanical macrofossils, chemical components and ancient DNA were studied in samples from the rumen of a frozen Yakutian bison (Bison priscus) that lived ca. 10,500 cal a BP. The dialkyl glycerol ether lipid archaeol (2,3-di-O-phytanyl-sn-glycerol) was detected and is interpreted to have been derived from methanogenic Archaea in the rumen. This is the oldest reported occurrence of archaeol attributed to digestive tract Archaea. Remains of shrubs (Alnus, Betula, Salix) and Poaceae indicate that the animal probably lived in a landscape of predominantly dry soils, intermixed with wetlands containing herbaceous plant species, as indicated by remains of Comarum palustre, Caltha palustris, Eriophorum, Sparganium, Menyanthes trifoliata and Utricularia. All recorded taxa still occur in the present-day Yakutian tundra vegetation. We discuss the representativeness in space and time of the methods used. Both the botanical microfossil and the macrofossil records may be biased because of differences in pollen production and dispersal between species, the food choice of the bison, and the season of death of the animal. Similarities and differences are discussed to highlight pitfalls of the individual analytical techniques. We highlight the power of data integration.