No -- sounds more to me like you have a spiney softshell turtle and it is just growing nomally. Look at the carapace near the top of the head. Is it smooth or sort of bumpy. If it is bumpy than that's what you have.
: My softy is growing spikes onthe rear of her shell. They used to be tiny dots- like acne- but its getting bigger and dirt is getting caught on it. My deduction is that she never goes completly out of water and the part that doesn't go out becomes rough??? I need someone with experience here. the ss is about 6 month old, 7" of shell.