Is an opposable thumb what makes me human?

Genesis 1:27 So God created man in his own image, in the image of God created he him; male and female created he them.

It was taught years ago that the opposable thumb raised us out of the animal kingdom to crown us as humans. But since then it has been discovered that other species have opposable thumbs - koalas and possums, for example. Oh no! Am I some sort of random iteration of cosmic ooze? Am I reduced to just another species to be memorized in biology class? Thumbs don't make us human. God made us in His image - that is what gives us dignity and worth. Humans who are blind or deaf or who have no legs or with downs syndrome are still human. Rejoice that you are fearfully and wonderfully made!