Dinosaurs still survive today as birds and Megalodon was bigger than Kronosaurus; meg is shark not a reptile but if you use the words "largest marine predator ever" it's not the kronosaur
Kronosaurus wasn't even the biggest predatory marine reptile either, it was around 10 m long, while it's cousin Pliosaurus was up to 13 m long, other marine reptiles like Mosasaurus were also larger.
