Since then, as the number of equid fossils has increased, the actual evolutionary progression from Eohippus to Equus has been discovered to be much more complex and multibranched than was initially supposed.
Senere har man erkendt, efterhånden som antallet af fundne fossiler er øget, at den faktiske evolutionære udvikling fra Eohippus til Equus var meget mere kompleks og mangegrenet end oprindeligt antaget.