The Stralusian Demi-Sharks are highly inteligent Shark-humanoids, that evolved and become the dominant species of the region of Stralusia. They are extant members of the Great White Sharks. The Demi-Sharks are a marine and terrestrial species, characterised by their erect posture, bipedal locomotion, marine tails that help them swim fast, high manual dexterity and and heavy tool use. They have a open ended and complex language system. They have similar sized and advanced brain systems of humans and highly advanced societies.
The Demi-Sharks evolved from the the modern Great White Shark and their ancient descendant the infamous Megaladon from 23 million years ago during the early Miocene to the Pilocene Eras.
The evolution of the Demi-Sharks was due to a radioactive meteorite that fell roughly five million years ago in the region that is now called the Stralusian Steppe. Five Million years ago the marine environment was a deep shallow ocean next to a small emerging land mass, it was home to a Shiver of Sharks, that were of different subspecies, larger than there modern day counterparts. It was predominately the subspecies that are called the Great White Sharks. There was a large Gam of them in the marine environment.
When the meteor fell it initially was the size of a modern semi detached house, by the time it got through the thin atmosphere it was the size of a car, the outer crust of the meteor had burnt off and gases were coming off it, the core was exposed and it was radioactive, it fell into the shallow recesses of near the shiver of sharks. Most of the sharks swam off a few died in the initial impact. Only a few of the Great White Sharks stayed in the area, over time the Sharks were exposed to the radiation and gases. and evolved to what is now called the Demi-Sharks.
The Demi-Sharks natural habitat are is the shallow and deep ocean, off the coast of the Stralusian Steppe, but as they are humanoid they can survive on the Steppe too. They can spend unlimited time on land and undersea, but they choose to live in the ocean, they have fashioned out caverns in the the sea cliff, which inside is a huge network of tunnels that are without water and oxygenated, as the network of small tunnel and caverns reach up to the Mountains above shore on thr Stralusian Steppe.
They're is a surprisingly large city, with modern houses, shops, hotels and tourist attractions near the entrance of the mountain that leads down to the deep sea caverns. It is called White Fin City.