摘要:SummaryThe evolution of the generaBosandBison, and the nature of gene flow between wild and domestic species, is poorly understood, with genomic data of wild species being limited. We generated two genomes from the likely extinct kouprey (Bos sauveli) and analyzed them alongside otherBosandBisongenomes. We found thatB. sauvelipossessed genomic signatures characteristic of an independent species closely related toBos javanicusandBos gaurus. We found evidence for extensive incomplete lineage sorting across the three species, consistent with a polytomic diversification of the major ancestry in the group, potentially followed by secondary gene flow. Finally, we detected significant gene flow from an unsampled AsianBos-like source into East Asian zebu cattle, demonstrating both that the full genomic diversity and evolutionary history of theBoscomplex has yet to be elucidated and that museum specimens and ancient DNA are valuable resources to do so.Graphical abstractDisplay OmittedHighlights•We generated two genomes from the likely extinct kouprey (Bos sauveli)•Extensivemtand nuclear-genome-wide incomplete lineage sorting across wild AsianBos•Initial polytomic diversification of the wild AsianBos—kouprey, banteng, and gaurBiological sciences; Evolutionary biology; Phylogenetics