This shark ate dinosaurs. Yup. A Squalicorax tooth was found embedded in the foot of a hadrosaur fossil, which the Cretaceous predator likely scavenged from shallow waters. The 15-foot Squalicorax was incredibly successful during its long reign, traveling all over the Mesozoic oceans. It specialized as a coastal predator, attacking fellow marine giants like mosasaurus and perhaps even taking down live terrestrial animals unlucky enough to fall into its territory. You can practically hear the hadrosaur in this illustration saying, "uh oh" as the Squalicorax circles it.
Artwork by Dmitry Bogdanov.