There are a large number of human ethnicities throughout the world. The Carnoscan city-states are home to quite a few themselves, the most common of which are the Mercaneans. A few others are listed here.
(Players: Feel free to create more.)
Ambronechean: A group of people from south of the Tychaendrian sea, from the marshland called Ambrona. They tend to be very dark skinned and dark haired, though they often shave their heads completely bald. One of the first people to be subjugated by Carnosca. Myrmidon Belltraza is of these people.
Hindalian: Related to the ancient Hindals, these are people who still live on the Hindala plateau. They tend toward tan skin and dark hair with large features. They very often live in simple nomadic tribes.
Ice Men: These are barbaric humans from north of the Great Northern Taiga, who dwell in the tundra and glaciers. Lore and rumor say they are cannibals, but not many have had contact with them. They tend to be larger than most humans with bronze skin and black hair.
Mercanean: Most common ethnicity in the northern parts of Carnosca. They are fairly dark skinned and often have dark hair. Beards are very common among males, usually these are styled especially among the noble caste.