Respected scientific community,

I am describing a new species of fauna and the papers I am citing/ referring to in my manuscript, seem to contain a bunch of comparative materials that the authors have used when comparing with their new species they were describing. Is it necessary to physically study the type/non type specimens themselves that are stored in national repositories and museums? Will referring to the literature that contains their data be considered legitimate? Maybe even collecting some specimens from the type locality or from personal collections?

Thanking You