 Multiple authors have suggested that the Sorraia might be a descendant of the Tarpan based on shared morphological features , principally the typical color of its coat . Other authors simply state that the Sorraia has " evident primitive characteristics " , although they do not refer to a specific ancestor . However , there have been no genetic studies comparing the Sorraia with the Tarpan , and similarity of external morphology is an unreliable measure of <unk> . 
