Interesting the North American vs European species.

Wapiti or American "elk" vs Red stag / deer

Moose vs European moose/alg/elg.
(American elk was misnamed after the elg, European moose.)

American bison aka "buffalo" vs Wisent European bison.

The European species are all smaller than the north American species. I assume they could interbreed.

Brown bear also exist in both places. Are inland American brown bears/grizzlys bigger than European brown bears? Almost certainly the well fed coastal Alaskan brown bears. But otherwise. Brown bears in Scandinavia, Romania, former Yugoslavian countries, elsewhere and of course Russia. The Russian brown bears have a reputation for size, of course those in Eastern Siberia, Kamchatka are just as big as the biggest North American BBs.

Interesting the species and the size differences. I wonder why the size differences?