The Image of a long-bodies, short-legged female dog with a pointed muzzle and erect ears was discovered cut into the rock of a tomb in Besheb Egypt. It dates from the period of the Middle Kingdom in the second millennium B.C.
Although this is NOT absolute proof that it is a direct line of Dachshunds, it does prove that dogs with extremely short legs and very long backs existed even then.
Without doubt, in ancient times and in different countries small dogs of varied appearances were used to pursue small game underground. Only later were definite types of such small dogs bred by deliberate selection; this naturally resulted in substantially different breeds.