Complex sentence: The plains were home to a type of equid that resembled a zebra called the Hagerman Horse, which will be represented by plains zebra or Grevy's zebra introduced into the Great Plains from Africa as part of the project.
Split into simpler sentences: The plains were home to a type of equid that resembled a zebra called the Hagerman Horse, which could be represented by plains zebra or Grevy's zebra. It would be introduced into the Great Plains from Africa as part of the project.