______ species are the species which are not found after searches of known or likely areas where they may occur.

The correct answer is Extinct.

Key Points

• Extinct species: 
  • If we say that any species is extinct we normally mean that the last existing member has died.
  • Extinction, therefore, becomes a certainty when there are no surviving individuals that can reproduce.

Additional Information 

• Endangered species:
  • Endangered species are the species which if not protected will become extinct in a short duration of time.
  • These species are protected and bred in conserved areas like national park sanctuaries.
  • These species may be at risk due to factors such as habitat loss, poaching, and invasive species.  
  • They have a very high risk of extinction in the wild but are still present in the wild in a few numbers.
• Endemic species:
  • These are the species whose plants and animal can be found in a particular geographical region and nowhere else in the world.