i adopted lily about a year ago (she was approximately 5 months old at the time) and her previous owners informed me that she was a rottie mix.  it has now become clear to me that this is impossible (she only weighs 30 pounds and has a completely different build), and that they probably assumed this based only on her coloring.  she is black with tan markings (feet, eyebrows, mask), which can be found in a number of different breeds.  at this point, i am reasonably convinced that she is some combination of australian cattle dog, kelpie, border collie, and/or australian sheepdog. 

if a more experienced eye can offer me some guidance, it would be much appreciated.  thanks!