What is the Difference between genus felis and genus panthera?

Answer 1

felis is a small cats and panthera is a big cats

The answer above is not quite correct. Oddly enough, the characteristic which taxonymists use to make the distinction between these two genii is the roar, or conversely, it's absence. There are only two members of the genus panthera found in the new world, the Lynx(Panthera lynx canadensis) and the Bobcat(Panthera lynx rufus). Although significantly larger than either of it's fellow Western Hemisphere co-habitants, The Puma, or as it is known in some parts, the Mountain Lion (Felis concolor) is endowed with a caterwaul (or 'scream') rather than a roar and is thus a member of Felinaerather than Pantherina.

There is one more genus present in the family felidaepopulated with but a single member. Acinonyx jubata, or more familiarly, the Cheetah is the fastest running of all the felines. (fastest running critter on the whole planet, for that matter..) The cheetah purrs but hasn't a roar. The characteristic which earns jubata it's very own genus is the lack of retractable claws. (I think that if I were tooling along, barefoot, at a brisk clip of 70 m.p.h. or so, I might be tempted to leave my claws out for traction as well!)

I hope that this answers your question clearly and adequately.