 The Sorraia is a rare breed of horse indigenous to the portion of the Iberian peninsula , in the Sorraia River basin , in Portugal . The Sorraia is known for its primitive features , including a convex profile and dun coloring with primitive markings . Concerning its origins , a theory has been advanced by some authors that the Sorraia is a descendant of primitive horses belonging to the naturally occurring wild fauna of Southern Iberia . Studies are currently ongoing to discover the relationship between the Sorraia and various wild horse types , as well as its relationship with other breeds from the Iberian Peninsula and Northern Africa . 
