Wyandottes do occasionally have a single comb, that's a variant, but not the standard.
Wyandottes are also slightly hard to tell sex of, both my GLW and my SLW were hard to sex. They were both girls. They did start to grow wattles early, but they were small and pink and not big and red.

This is my FEMALE GLW at 3 weeks old... see the wattles developing and turning pink? I swore she was a boy. According to the boards, this question is asked a lot, many female GLW get pink like this.
Wyandottes are also slightly hard to tell sex of, both my GLW and my SLW were hard to sex. They were both girls. They did start to grow wattles early, but they were small and pink and not big and red.
This is my FEMALE GLW at 3 weeks old... see the wattles developing and turning pink? I swore she was a boy. According to the boards, this question is asked a lot, many female GLW get pink like this.