If you read those articles I've posted, you'll see they do get confused over what way to go.
Also...I'm not about to get into a war over something so silly. Like I said before...it IS very common in mammals but they rarely survive past infancy. I've seen pigs, buffalos, cows, horses, cats, people...on and on. For whatever reason, the snakes and turtles survive better then mammals do. But even then, it's a low percentage that do survive. It's just enough to make it seem like it happens more often in reptiles.
I also think that in reptiles, it's view as a neat oddity and is pretty well received publicly. With mammals, it's often viewed as a horrible mutation and is kept a little more under the covers (in a way). It's more difficult to find mammal picture for this reason (I believe), but TRUST me they are out there. I just won't post them because many of the sites are not family friendly.