As the period came to a close ... in the seas was the appearance of whales in the mid- to late Paleogene. The huge animals evolved from land mammals that took to the seas. Meanwhile, smaller ...

The class of animals that we refer to as “reptiles ... during the early part of the Paleogene period. The ancient mosasaur, a giant marine lizard, was a formidable predator that thrived ...

Several factors contributed to the survival of crocodiles, turtles, lizards and birds 66 million years ago, say our readers ...

With animals, whole groups disappeared ... When the Cretaceous Period and Mesozoic Era ended 66 million years ago, the Palaeogene Period and the Cenozoic Era began. In the Palaeogene, the continents ...