Wikipedia cites:
(September 2002) in Trewby, Mary (ed.): Antarctica: An Encyclopedia from Abbott Ice Shelf to Zooplankton. Firefly Books. ISBN 1-55297-590-8.
As a source for:
MYA = Million years ago.Africa separated from Antarctica around 160 mya, followed by the Indian subcontinent, in the early Cretaceous (about 125 mya). About 65 mya, Antarctica (then connected to Australia) still had a tropical to subtropical climate, complete with a marsupial fauna. About 40 mya Australia-New Guinea separated from Antarctica, so that latitudinal current could isolate Antarctica from Australia, and so the first ice began to appear. Around 23 mya, the Drake Passage opened between Antarctica and South America, which resulted in the Antarctic Circumpolar Current. The ice spread, replacing the forests that then covered the continent. Since about 15 mya, the continent has been mostly covered with ice,[26] with the Antarctic ice cap reaching its present extension around 6 mya.
Dinosaurs lived well before that time period. However, it would have been cold.
http://www.smithsonianmag.com/histor...rs-200712.html This article is about the Antarctic dinosaurs (though only two kinds have been found to date, so it wasn't exactly full of dinos). It states the climate would have been similar to Chicago's modern climate. That could mean dinosaurs hibernated during the winter, as reptiles do in temperate climates
I live in Sweden and we do have snakes and lizards here too. The trick is to sleep through the winters.
Also: this is fantasy. Dragons can live in cold. White dragons f-ing breath what must be liquid nitrogen. Why can't we have dinosaurs that can see color?
EDIT:
Reptilia (or Sauropsida as it is also called) is a Class, not an Order.2) So? The dinosaurs are another evolutionary route taken by reptiles, but they are still classified under the Order Reptilia.
Science: serious business.