"The dinosaurs, and the mammals and other creatures buried with them, were buried during the global flood of Noah's day just 4,350 years ago. The various rock layers don't represent different geological ages. Rather, they represent different ecological zones, buried as the floodwaters rose. All the original mammal kinds lived at the same time as the dinosaurs (and, for the land-dwelling mammal kinds, representatives were on the same ark with the dinosaurs), alongside humans..."
https://answersingenesis.org/dinosaurs/when-did-dinosaurs-live/dispelling-paleontological-myths-and-false-narratives/