I should have added above that surnames often were related to the particular place where the people originally lived. So, we get Moore, for example, which probably meant the first people so called lived outside a settlement and on the edge of the surrounding moors.
One meaning of 'shaw' - Shawland being one of the variants of your name, Shortland - was a small wood and another meant the furthest part of cultivated land. It is quite likely, therefore, that your ancestors lived pretty much "on the end of town" or just outside it, as it were!