Jan Martin

Doctor Jan Martin was a human who lived on the alternate Earth ruled by the Silurians. She was part of an expedition to London to acquire medical supplies for Jo Grant.

Jan was killed along with all the other inhabitants of that universe when the Seventh Doctor time rammed his TARDIS with the one he acquired there, destroying that universe. This was because the energy used by the alternate timeline shortened the existence of the main universe by billions of years. (PROSE: Blood Heat)