holotype

/ˈhɑləˌtaɪp/
noun
  1. The single physical example of an organism used to officially describe and name a new species.
    • The museum keeps the holotype of the dinosaur species in a special climate-controlled room.
    • Scientists compared the new fossil to the holotype to confirm it was the same species.
    • The holotype of this butterfly was collected in Brazil over a hundred years ago.