I always thought Shelties were just small Collies? LOL, am I wrong? That dog looks like every Collie I've ever seen. . .
I know they're separate breeds NOW. And I know they developed in different areas. But I thought their backgrounds were of the same types. But, as I said, that dog looks just like every Collie I've ever seen, and every Sheltie I've ever seen looks like a small Collie. So I guess I can't think of any difference in appearance between a regular-sized Collie and a large Sheltie.
Collies were a landrace breed. The original dogs were more along the lines of a general farm dog. You have a lot of breeds that eventually come out of this general dog. Border collies, Welsh Sheepdogs, Rough and Smooth Collies, Shelties, English Shepherds, Koolies, Aussies, Bearded Collies, etc. All have various relation to each other. All distinct breeds, bred for different types of work/show.
A sheltie isn't a collie in miniature. It's not a size variety of a rough collie like miniature poodles and standard poodles are a size variety. It's kind of like the same way the MAS isn't a true 'miniature aussie'. Shelties come from completely different foundation stock on the shetland islands. They were not very set in type but were crossed often to dogs that were border collie-esque from the mainland. The Victorian age show collie was also being developed at the same time and people decided to push shelties towards a more uniform type, which ended up being the rough collie look. To do so, they snuck in show collies and called them unregistered shelties. It's part of why there's such a size issue in the breed.
Shelties and collies also
do look different and have different proportions and head types though and so on. It's probably less apparent if you don't have either breed, but I can tell from a picture right away if it's a sheltie or a collie. Shelties also come in more colors/patterns than collies. Shelties can be bicolor, collies cannot. They're always tri (merle or black) or sable. Shelties don't come in coat varieties either, whereas collies do. They also have different temperaments from collies.