Why Do Mammals Have Fur?: And Other Questions About Evolution and Classification
POWERKIDS PRESS WILDLIFE WONDERS Why Do Mammals Fur Have And Other Questions About Evolution and Classification PAT JACOBS
What is a mammal Mammals are warm blooded animals This means that they can keep their bodies at the same temperature by burning food to keep warm Mammals breathe air and most have hair on their bodies Mammal mothers all produce milk to feed their babies This mammal like reptile named Estemmenosuchus lived 255 million years ago How mammals evolved Mammals are descended from mammal like reptiles that lived around 260 million years ago Most of these creatures had died out by the start of the Mesozoic era the age of the dinosaurs but a few survived and developed into the first true mammals The first true mammals were similar to modern day shrews The first mammals The first real mammals were shrew like animals that lived alongside the dinosaurs and probably ate insects Because they were warm blooded they were able to hunt at night when the cold blooded dinosaurs were asleep The little mammals developed good senses of smell and hearing so they could find their prey in the dark TIMELINE CENOZOIC ERA MESOZOIC ERA 252 66 million years ago mya Paleocene 65 56 mya Eocene 34 56 mya
23 5 5 1.8 1.8 10,000 10,000 Holocene Pleistocene Pliocene Miocene now ya ya mya mya mya mya 23 34 Oligocene Mammals inherit the Earth At the end of the Mesozoic era a catastrophic event wiped out all the dinosaurs Most scientists believe that an asteroid struck the Earth and sent up a huge cloud of dust which blocked out the Sun so plants could not grow Without competition from the dinosaurs the little mammals quickly evolved into many different groups THE AGE OF MAMMALS Mammals are the only animals that suckle their babies Smilodon is one of the best-known saber-toothed cats It lived during the Pleistocene epoch 30 20 10
