Argent... yes, that was my first thought too, I'm ashamed to say.
Aaron L -- yes, ursids (bears) and canids (dogs, wolves, foxes, etc) are both arctoid carnivores, which means they are from one branch of the carnivore family tree (which is seperate from the aureloid branch with it's cats and hyenas) but so are mustelids (weasels, otters, wolverines, badgers) and a few other various critters, like mongooses and seals (!). There are also some extinct groups, including some that are sorta hybrids in body plan between wolves and bears. There were also various other niches the clan spread out into over the years -- the short faced bear which went extinct only a few thousand years ago and is relatively common at La Brea was a slim(mish) bear with long legs; probably an active hunter and good runner, and the largest carnivore (from the order Carnivora -- obviously things like
T. rex were bigger) ever. The dire wolf isn't really a big wolf, it's a robust, powerfully built dog of some kind, with very large, strong jaws. It's believed they may have been borophagine, that is, they chomped on the entire carcass, bones and all, somewhat hyena-like. There were a lot of North American "dogs" that followed this particular niche over the last several million years.
Ravellion -- yeah, none of the cats have ever really been bigger than a Siberian tiger, really. Some have been about as big, or lion sized at least (which is still pretty frikkin big, really) but this myth that ancient mammals were all humongous really is that, a myth. Although there really was a giant "beaver" during the interglacials of North America.