Are there skeletal differences between races?
Yes, there are actually cases of bone related problems due to race.
The Africoid race could get a bone disease if they live in a cold country where the sunlight is rarely felt and the melanin level in their skin is too high thus they become vitamin D deficient. This disease is called Rickets. For the Caucasoid and the Asian/Malay Race, osteoporosis is more common in the women.