Molecular analyses of dinosaur osteocytes support the presence of endogenous molecules

► Multiple lines of evidence support endogeneity of osteocyte-like microstructures in two dinosaurs. ► We show the first binding of bone-specific monoclonal antibody to 'cells' of these dinosaurs. ► Four independent lines of evidence support the presence of a component chemically consistent with DNA. ► We propose a novel mechanism for the preservation of these materials over geological time.