Scientists have discovered a 74-million-year-old fossil of a tiny, mouse-sized mammal named Yeutherium pressor in Chilean Patagonia. This mammal lived during the Upper Cretaceous period alongside dinosaurs and represents the third species from this era found in Chile, offering new insights into evolutionary transitions. Separately, paleontologists in Australia have identified a new species of ancient whale from a 25-million-year-old fossil found on a beach. Named Janjucetus dullardi, this whale had distinctive cartoonish bulging eyes resembling a Pokémon but was a fearsome predator with razor-sharp teeth. The discovery challenges previous perceptions of whale ancestors, revealing they were small, unusual, and feral creatures. The Australian fossil is considered a rare find that could unlock mysteries about whale evolution. Both discoveries highlight significant advances in understanding prehistoric mammals and marine predators.