Mark Sheppard
From Tardis Wiki, the free Doctor Who reference
Mark Sheppard portrayed a young version of Canton Everett Delaware III in the opening two parter of Series 6 of Doctor Who, The Impossible Astronaut and Day of the Moon. His father, William Morgan Sheppard, portrayed an older version of the character in the opening episode.
Sheppard is also well known for the amount of telefantasy series he has appeared in, including The X Files, Star Trek:Voyager, Firefly, Battlestar Galactica, Dollhouse and Supernatural amongst others.
