The notion of the Anthropocene has become an instrumental backdrop against which post-foundationalist social theory and political research frame the possibilities and prospects of governance to defy the certainty and, somewhat paradoxically, the anthropocentrism of modernity, under conditions of drastic ecological changes. But what exactly is the theoretical promise of the Anthropocene? This paper seeks to explore what the concept can offer to critical social science and, conversely, how these critical approaches define and locate the analytical and the political purchase of the Anthropocene. Taking a genealogical look at the Anthropocene concept as used in social sciences, this paper retraces the transition from a science-lead, discontinuous-descriptive to a continuous-ontological conceptualisation of the Anthropocene through different uses of the concept of deep time. It then unpacks how the notions of ecological relationality and non-human agency deployed in the latter closely parallel certain lines of argumentation in Indigenous thought and politics. Drawing on Critical Indigenous Studies, the paper formulates a critique of how relational perspectives enfold alternative ontologies and politics within an overarching Anthropocene ontology which is not only problematically universalising, but also replaces the genuine engagement with differences and resistance.