These offspring were called Spanish Jennets. The Spanish Jennet is the horse brought to Peru by the conquistadors in 1536. The Barb was a common looking horse compared to the Arabian and was bred out of existence in Europe. People like to see pretty heads, short backs and high action, all traits of the trotting breeds. Even now, in the showing, you see more value placed on looks, rather than efficiency of movement.
Research can be valuable in respect to DNA and skeletal features, such as the number of vertebrae.
This information can help us preserve the purity of the breed. The latter features are characteristic of trotting horses. As load increases, trotting horses go to two legs of diagonal support. When Paso horses increase speed with a 4 beat tempo, the horses with the hip in front of the last lumbar vertebrae have less over step and subsequently more stress on the suspensory ligaments. They will also have some vertical hock movement, resulting in vertical tail movement.