The first mammals probably evolved from reptiles about 200 million years ago during the Mesozoic period. They were rather small in a time when dinosaurs ruled the lands. When the dinosaurs died out about 65 million years ago, mammals became the dominant land animals. Many mammals became extinct during the Ice Age , which ended thousands of years ago.

Today, some species are in constant danger of becoming extinct because they are hunted by humans. Hunters and poachers earn money by selling fur, tusks and other parts of mammals. Larger wild animals are often brought to zoos where they are protected.



Artist's image of wooly mammoths during the Ice Age
Image : Charles R. Knight, Public domain, via Wikimedia Commons


Words

  • constant = always
  • dominant = number one
  • evolve = develop. grow
  • extinct = die out
  • fur = thick soft hair that covers the bodies of animals
  • Ice Age = one of the long periods of time thousands of years ago when ice covered a large part of the northern continents
  • Mesozoic period = the geologic middle ages of the earth
  • poacher = someone who catches or shoots animals illegally
  • protect = here: live safely
  • rather = pretty
  • reptile = animal like a snake or lizard, whose body temperature changes depending on the temperature around it 
  • rule= here : to be dominant; to have power over others
  • species = group of animals or plants that are alike and can produce young ones
  • tusk = long, curved tooth of an elephant