This thesis provides a biographical account of the aurochs, the wild and extinct ancestor to cattle, through the lens of time. It argues that the aurochs, as a scientific object that spans multiple time scales and has been studied through various disciplinary lenses, is best understood by foregrounding its temporality as a processual entity – one that is in a state of constant change and transformation. Since the nineteenth century, the aurochs has been seen as a representative of different times: a signifier of a past wilderness, of a prehuman world, of a world that saw the evolution of humanity, of a future of unpredictable climates. By providing a biographical account of the aurochs and tracing its study across different historical and cultural contexts, the thesis demonstrates how objects like the aurochs can bridge disciplinary boundaries and bring together different approaches to knowledge. As episodes in this dissertation demonstrate, pursuit of holistic inquiry into an object of cultural and scientific salience can provide a helpful foil for historical expectations of how the object might otherwise have been cleaved. The scope of this thesis includes an informal network of aurochs interlocutors who pursued study of the aurochs from the nineteenth century to the present, and who integrated the different timescales of their fields of work to do so. It examines the aurochs through paleontology in nineteenth-century Europe, and in particular Britain and nineteenth-century Colonial India; turn-of-the-century British and American breeding and genetics institutions; Nazi Germany; and contemporary rewilding in the Netherlands. This thesis offers contributions to historical understanding of interdisciplinary research, and the challenges of studying systems with multiple time scales.